CONTRIBUTIONS
to
THE NATURAL HISTORY
of the
UNITED STATES OF AMERICA
by
LOUIS AGASSIZ
First Monograph
in Three Parts - I.
Essay on Classification - II. North American Testudinata - III. The
Embryology of the Turtle
With Thirty-Four Plates
Volume I and
Volume II
BOSTON:
LITTLE, BROWN AND COMPANY.
LONDON:
TRUEBNER & CO.
1857.
643 + 51 pages + 34 plates and 11 woodcuts.
Dedication v v
Preface vii vii
viii
ix
x
xi
xii
xiii
xiv
xv xvi
VOLUME I
CONTENTS.
PART I.
ESSAY ON CLASSIFICATION.
CHAPTER I.
THE FUNDAMENTAL RELATIONS OF ANIMALS
TO ONE ANOTHER AND TO
THE WORLD IN WHICH THEY LIVE, AS THE BASIS OF THE NATURAL SYSTEM OF
ANIMALS.
SECTION 1. The leading features of a natural zoological system are all
founded in nature. 003
004
005
006
007
008
009
010
011
012
There is but one system, and that is to
be read in nature, and was not devised by man. The essential divisions
of that system cannot be arbitrary, p. 3-12.
SECTION 2. Simultaneous existence of the most diversified types under
identical circumstances. 012
013
014
015 016
Organized beings of the most different
structure are everywhere found together, p. 12-16.
SECTION 3. Repetition of identical types under the most diversified
circumstances. 016
017
Organized beings with the same
structure occur in the most different parts of the world, p. 16-17.
[017] When naturalists have investigated the influence of physical
causes upon living beings, they have constantly overlooked the fact
that the features which are thus modified are only of secondary
importance in the life of animals and plants, and that neither the plan
of their structure, nor the various complications of that structure,
are ever affected by such influences. What, indeed, are the parts of
thw body which are, in any way, affected by external influences?
Chiefly those which are in immediate contact with the external world,
such as the skin... then the size of the body and its weight... the
thickness of the shell of Mollusks, when they live in waters or upon a
soil containing more or less limestone, etc.
SECTION 4. Unity of plan in otherwise highly diversifited
types. 018
019
The greatest diversity of form and of
complication of stricture may be found under the same plan of
structure, p. 18-19.
[018] Nothing is more striking throughout the animal and vegetable
kingdoms than the unity of plan in the structure of the most
diversified types.
SECTION 5. Correspondence in the details of structure in animals
otherwise entirely disconnected. 019 020
021
Animals, between which no genetic
relation can be traced, may nevertheless exhibit the most astonishing
correspondence in the details of their structure, p. 19-21.
[019] During the first decade of this century, naturalists began to
study relations among animals which had escaped almost entirely the
attention of earlier observers...it is only recently that anatomists
have eiscovered the close correspondence which exists between all the
parts of all animals belonging to the same type, however different they
may appear at first sight. Not only is the wing of the bird identical
in its structure with the arm of man, or the fore leg of a quadruped,
it agrees quite as closely with the fin of the whale, or the pectoral
fin of the fish, and all these together correspond in the same manner
with their hind extremities. ...But this correspondence is not limited
to the skeleton; every other system of organs exhibits in these animals
the same relations, the same identity in plan and structure, whatever
be the differences in the form of the parts....Such an agreement in the
structure of animals is called their homology, and is more or less
close in proportion as the animals in which it is traced are more or
less nearly related.
SECTION 6. Various degrees and different kinds of relationship
among animals. 021
022
023
Animals differ from one another, not
only in degree; there are also different kinds of differences, p. 21-23.
SECTION 7. Simultaneous existence in the earliest geological
periods of all the great types of animals. 023
024
025
The leading types of the animal kingdom
have made their appearance upon the surface of our globe at the same
time, p. 23-25.
[023] It was formerly believed by geologists and palaeontologists that
the lowest animals first made their appearance upon this globe, and
that they were followed by higher and higher types, until man crowned
the series. Every geological museum, representing at all the present
state of our knowledge, may now furnish the evidence that this is not
the case. On the contrary, representatives of numerous families
belonging to all the four great branches of the animal kingdom, are
well known to have existed simultaneously in the oldest geological
formations....[N]either Radiata, nor Mollusks, nor Articulata, have any
priorit over thye other, as to the time of their first appearance upon
earth...[F]ishes exist wherever Radiata, Mollusks, and Articulata are
found together, and the plan of structure of these four great types
constitutes a system intimately connected in its very essence... [T]he
idea of a gradual succession of Radiata, Mollusks, Articulata, and
Vertebrara, is for ever out of the question. It is proved beyond doubt,
that Radiata, Mollusca, and Articulata are everywhere found together in
the oldest geological formations, and that very early Vertebrata are
associated with them, to continue together through all geological ages
to the present time....
This is not all: every class
among Radiata, Mollusks, and Articulata, is known to have been
represented in those earliest days, with the exception of the Acalephs
and Insects only. ...so that the assumption of a successive
introduction of these types upon earth is flatly contradicted by well
established and well known facts.... But when we come to the orders,
it can hardly be doubted that the gradation of these natural divisions
among themselves in each class, constitutes the very essence of this
kind of groups. [empahsis added -- dcb]
SECTION 8. The gradation of structure among animals. 026
027 028
029
030
There is a gradation among
animals, though they do not form one continuous series, p. 26-30.
SECTION 9. Range of geographical distribution of animals. 030
031
032
033
034
035
036
The range of distribution
of different kinds of animals is very unequal. Faunie, p. 30-36.
[032] [V]arious animals and plants were respectively adapted with all
the peculiarities of their kingdom, those of their class, those of
their order, those of their genus, and those of their species, to the
home assigned to them, and therefore, not produced by the nature of the
place, or of the element, or any other physical condition....In other
words, in all these animals and plants, there is one side of their
organization which has an immediate reference to the elements in which
they live, and another which has no such connection, and yet it is
preciselythis part of the structure of animals and plants, which has no
direct bearing upon the conditions in which they are placed in nature,
which constitutes their essential, their typical character. this proves
beyond the possibility of an objection, that the elements in which
animals and plantes live (and under this expression I mean to include
all that is commonly called physical agents, physical causes, etc.,)
cannot in any way be considered as the cause of their existence.
SECTION 10. Identity of structure of widely different types. 036
037
038
039
040
Animals found within
entirely disconnected areas may have the same
structure, p. 36-40.
[039] [M]ore extensive and precise knowledge of the geographical
distribution of organized beings forced upon its cultivators the
conviction, that neither animals nor plants could have originated upon
one and the same spot upon the surface of the earth, and hence have
spread more and more widely until the whole globe became inhabited. It
was really an immense progress which freed science from the fetters of
an old prejudice. ... But even to grant distinct centres of
distribution for each species within their natural boundaries, is only
to meet the facts half way, as there are innumerable relations between
the animals and plants which we find associated everywhere, which must
be considered as primitive, and cannot be the result of successive
adaptation....Pines have originated in forests, heaths in heathers,
grasses in prairies, bees in hives, herrings in schools, buffaloes in
herds, men in nations! .
[040] I confess that nothing has ever surprised me so much as to see
the perfect identity of the most delicate microscopic structures of
animals and plants, from the remotest parts of the world. It was this
striking identity of structure in the same types, this total
independence of the essential characteristics of animals and plants, of
their distribution under the most extreme climatic differences known
upon our globe, which led me to distrust the belief, then almost
universal, that organized beings are influenced by physical causes to a
degree which may essentially modify their character.
SECTION 11. Community of structure among animals living in
the
same regions. 041
042
043
Animals occupying the same
region exhibit sometimes a
remarkable similarity of structure, p. 41-43.
SECTION 12. Serial connection in the structure of animals widely
scattered upon the surface of our globe. 043
044
045
046
047
Animals living in different parts of
the world form frequently series which are
closely linked together, p. 43-47.
SECTION 13. Relation between the size of animals and their
structure. 047
048
049
Though apparently of secondary
importance, the size of animals bears a definite relation to their
trueture, p. 47-49.
SECTION 14. Relation between the size of animals and the mediums in
which they live. 049
050
There is also a definite relation
between
the size of animals and the mediums in which they live, p. 49-50.
SECTION 15. Permanency of specific peculiarities in all organized
beings. 051
052
053
054
055
056
Immutability of species. p. 51-56.
SECTION 16. Relations between animals and plants and the surrounding
world. 057
058
059
060
061
062
063
There exist definite
relations between the animals and plants, and the conditions under
which the live. Habits of animals. p. 57-63.
SECTION 17. Reiations of individuals to one another. 063
064
065
066
The relations in which individual
animals stand to one another are well defined in nature, p. 63-66.
SECTION 18. Metamorphoses of animals. 066
067
068 069
070
071
072
073 074
075
076
077
078
079
080
081
082 083
084
085
086
087
088
Importance of
Embryology. Works upon this subject. Polypi, Acalephs,
Echinoderms, Classes of Radiata. Mollusks, their affinities and
development. Articulata, their range and affinities. Worms,
Crustacea, Insects. Vertebrata. Embryology furnishes standards to
determine the relative rank among animals. Distinction between
homologies and analogies. Independence of the development of animals
from external causes. p. 66-88.
[068] The universal presence of eggs in all animals and the unity of
their structure ... constitute, in my opinion, the greatest discovery
of modern times in the natural sciences.
SECTION 19. Duration of Life. 088
089
There is the greatest
diversity in
the average duration of the life of different kinds of animals, p.
88-89.
SECTION 20. Alternate generations. 090
091
092
093
There are animals the successive
generations of which are not identical, though their diflrences are
circumscribed within definite cycles, p. 90-93.
SECTION 21. Succession of animals and plants in geological times.
098
099
100
101
The
succession of organized beings in past geological ages exhibits
biological phenomena of the most complicated nature, requiring an
extensive acquaintance with
Zoölogy, Comparative Anatomy, and Embryology, to be rightly
appreciated. Works relating to the fossil
remains of different classes and of different geological periods.
Difference between the organic and inorganic kingdoms. p. 98-101.
[094] What amount of labor and patience it has cost only to
establish the fact, that fossils are really the remains of animals and
plants that once actually lived upon earth...Then it had to be proved,
that they are not the wrecks of the Mosaic deluge, which, for a time
was the prevailing opiniion, even among scientific men. After Cuvier
had shown, beyond question, that they are the remains of animals no
longer to be found upon the earth, among the living, Palaeontology
acquired for the first time a solid basis. Yet what amount of labor it
has cost to ascertain, by direct evidence, how these remains are
distributed in the solid crust of our globe, what are the differences
they exhibit in successive formations, what is their geographical
distribution! ...One result, however, stands now unquestioned: the
existence during each great geological era of an assemblage of animals
and plants differing essentially for each period.
SECTION 22. Location of types in past ages. 102
103
The geographical
distribution of some types of animals was circumscribed
within similar limits in past ages and now, p. 102-103.
SECTION 23. Limitation of species to particular geological
periods. 104
105
106
Not only species, but all
other groups of animals and
plants, have a definite range or duration, p.104-106.
SECTION 24. Parallelism between the geological succession of animals
and plants and their present relative standing. 107
108
109
110
111
112
The relative rank or
the animals now living coincides with the order of succession of their
representatives in past ages p.107-112.
[107] The total absence of the highest representatives of the animal
kingdom in the oldest deposits forming part of the crust of our globe,
has naturally led to the very general belief, that the animals which
have existed during the earliest period of the history of our earthy
were inferior to those now living, nay, that there is a natural
gradation from the oldest and lowest animals to the highest now in
existence. to some extent this is true; but it is certainly not true
that all animals form one simple series from the earliest times, during
which only the lowest types of animals would have been represented, to
the last period, when Man appeared at the head of the animal creation.
SECTION 25. Parallelism between the geological succession of animals
and the embryonic growth of their living representatives. 112
113
114
115 116
The changes which animals
undergo during their embryonic growth coincide also with the order of
succession
of the fossils of the same types in past ages. p. 112-116.
[115] It may be considered as a general fact, that the phases of
development of all living animals correspond to the order of succession
of their extinct representatives in past geological times. As far as
this goes, the oldest representatives of every class may then be
considered as embryonic types of their respective orders or families
among the living
SECTION 26. Prophetic types among animals. 116
117
118
Distinction between
prophetic, pregressive and synthetic types. A deeper insight into
these relations is indespensable in order to appreciate the
succession of' organized beings in past times, p. 116-118.
SECTION 27. Parallelism between the structural gradation of animals and
their embryonic growth. 118
119 120
The phases of development
of animals coincide with the different levels
in the gradation of their respective types. p. 118-120.
SECTION 28. Relations between the structure, embryonic growth,
geological succession, and the geographycial distribution of
animals. 120
121
122
The
geographical distribution of animals upon the surface of the globe
bears direct relations to the rank, the embryonic growth, and the
geological succession of
their respective types, p. 120-122.
SECTION 29. Mutual dependence of the animal and vegetable
kingdoms. 122
123
The animal and vegetable
kingdoms are dependent upon one another, and stand in harmonious
relation. p. 122-123.
SECTION 30. Parasitic animals and plants. 123
124
125
126
127
Various degrees and
difl'erent kinds of parasitism among animals and plants. Parasites do
not form natural groups p. 123-127.
SECTION 31. Combination in time and space of curious kinds of relations
among animals. 127 128
129
130
131
There a striking relation
between the
rank of animals. their embryonic growth, their geological
succession, and their geographical distribution, but even etween
organized
beings and some of the members of our solar system. p.
127-131.
SECTION 32. Recapitulation. 132
133
134
135
136
Bearing of the points
considered in the preceding Sections upon the question of the origin of
organized beings. What Classification should be. p. 132-136.
[132-136]
1st. The connection of all these known features of nature into one
system exhibits thought, the most comprehensive thought, in limits
transcending the highest wonted powers of man.
2d. The simultaneous existence of the most diversified types under
identical circumstances exhibits thought, the ability to adapt a great
variety of structures to the most uniform conditions.
3d. The repetition of similar types, wider the most diversified
circumstances, shows an immaterial connection between them; it exhibits
thought, proving directly how completely the Creative Mind is
independent of the influence of a material world.
4th. The unity of plan in otherwise highly diversified types of
animals, exhibits thought; it exhibits more immediately premeditation,
for no plan could embrace such a diversity of beings, called into
existence at such long intervals of time, unless it had been framed in
the beginning with immediate reference to the end.
5th. The correspondence, now generally known as special homologies, in
the details of structure in animals otherwise entirely disconnected,
down to the most minute peculiarities, exhibits thought, and more
immediately the power of expressing a general proposition in an
indefinite number of ways, equally complete in themselves, though
differing in all their details.
6th. The various degrees and different kinds of relationship among
animals which can have no genealogical connection, exhibit thought, the
power of combining different categories into a permanent, harmonious
whole, even though the material basis of this harmony be ever changing.
7th. The simultaneous existence, in the earliest geological periods in
which animals existed at all, of representatives of all the great types
of the animal kingdom exhibits most especially thought, considerate
thought, combining power, premeditation, prescience, omniscience.
8th. The gradation based upon complications of structure which may be
traced among animals built upon the same plan, exhibits thought, and
especially the power of distributing harmoniously unequal gifts.
9th. The distribution of some types over the most extensive range of
the surface of the globe, while others are limited to particular
geographical areas, and the various combinations of these types into
zoölogical provinces of unequal extent, exhibit thought, a close
control in the distribution of the earth's surface among its
inhabitants.
10th. The identity of structure of these types, notwithstanding their
wide geographical distribution, exhibits thought, that deep thought
which, the more it is scrutinized, seems the less capable of being
exhausted, though its meaning at the surface appears at once plain and
intelligible to every one.
11th. The community of structure in certain respects of animals
otherwise entirely different, but living within the same geographical
area, exhibits thought, and more particularly the power of adapting
most diversified types with peculiar structures to either identical or
to different conditions of existence.
12th. The connection, by series, of special structures observed in
animals widely scattered over the surface of the globe, exhibits
thought, unlimited comprehension, and more directly omnipresence of
mind, and also prescience, as far as such series extend through a
succession of geological ages.
13th. The relation there is between the size of animals and their
structure and form, exhibits thought; it shows that in nature the
quantitative differences are as fixedly determined as the qualitative
ones.
14th. The independence, in the size of animals, of the mediums in which
they live, exhibits thought, in establishing such close connection
between elements so influential in themselves and organized beings so
little affected by the nature of these elements.
15th. The permanence of specific peculiarities under every variety of
external influences, during each geological period, and under the
present state of things upon earth, exhibits thought: it shows, also,
that limitation in time is an essential element of all finite beings,
while eternity is an attribute of the Deity only.
16th. The definite relations in which animals stand to the surrounding
world, exhibit thought; for all animals living together stand
respectively, on account of their very differences, in different
relations to identical conditions of existence, in a manner which
implies a considerate adaptation of their varied organization to these
uniform conditions.
17th. The relations in which individuals of the same species stand to
one another, exhibit thought, and go far to prove the existence in all
living beings of an immaterial, imperishable principle, similar to that
which is generally conceded to man only.
18th. The limitation of the range of changes which animals undergo
during their growth, exhibits thought; it shows most strikingly the
independence of these changes of external influences, and the necessity
that they should be determined by a power superior to these influences.
19th. The unequal limitation in the average duration of the life of
individuals in different species of animals, exhibits thought; for,
however uniform or however diversified the conditions of existence may
be under which animals live together, the average duration of life, in
different species, is unequally limited. It points, therefore, at a
knowledge of time and space, and of the value of time, since the phases
of life of different animals are apportioned according to the part they
have to perform upon the stage of the world.
20th. The return to a definite norm of animals which multiply in
various ways, exhibits thought. It shows how wide a cycle of
modulations may be included in the same conception, without yet
departing from a norm expressed more directly in other combinations.
21st. The order of succession of the different types of animals and
plants characteristic of the different geological epochs, exhibits
thought. It shows, that while the material world is identical in itself
in all ages, ever different types of organized beings are called into
existence in successive periods.
22d. The localization of some types of animals upon the same points of
the surface of the globe, during several successive geological periods,
exhibits thought consecutive thought; the operations of a mind acting
in conformity with a plan laid out beforehand and sustained for a long
period.
23d. The limitation of closely allied species to different geological
periods, exhibits thought; it exhibits the power of sustaining nice
distinctions, notwithstanding the interposition of great disturbances
by physical revolutions.
24th. The parallelism between the order of succession of animals and
plants in geological times, and the gradation among their living
representatives, exhibit thought; consecutive thought, superintending
the whole development of nature from beginning to end, and disclosing
throughout a gradual progress, ending with the introduction of man at
the head of the animal creation.
25th. The parallelism between the order of succession of animals in
geological times and the changes their living representatives undergo
during their embryological growth, exhibits thought; the repetition of
the same train of thoughts in the phases of growth of living animals
and the successive appearance of their representatives in past ages.
26th. The combination, in many extinct types, of characters which, in
later ages appear disconnected in different types, exhibits thought,
prophetic thought, foresight; combinations of thought preceding their
manifestation in living forms.
27th. The parallelism between the gradation among animals and the
changes they undergo during their growth, exhibits thought, it
discloses everywhere the most intimate connection between essential
features of animals which have no necessary physical relation, and can,
therefore, not be understood otherwise than as established by a
thinking being.
28th. The relations existing between these different series and the
geographical distribution of animals, exhibit thought; they show the
omnipresence of the Creator.
29th. The mutual dependence of the animal and vegetable kingdoms for
their maintenance, exhibits thought; it displays the care with which
all conditions of existence, necessary to the maintenance of organized
beings, have been balanced.
30th. The dependence of some animals upon others or upon plants for
their existence, exhibits thought; it shows to what degree the most
complicated combinations of structure and adaptation can be rendered
independent of the physical conditions which surround them.
We may sum up the results of this discussion, up to this point, in
still fewer words: -
All organized beings exhibit in themselves all those categories of
structure and of existence upon which a natural system may be founded,
in such a manner that, in tracing it, the human mind is only
translating into human language the Divine thoughts expressed in nature
in living realities.
All these beings do not exist in consequence of the continued agency of
physical causes, but have made their successive appearance upon earth
by the immediate intervention of the Creator. As proof, I may sum up my
argument in the following manner:
The products of what are commonly called physical agents are everywhere
the same, (that is, upon the whole surface of the globe,) and have
always been the same (that is, during all geological periods); while
organized beings are everywhere different and have differed in all
ages. Between two such series of phenomena there can be no causal or
genetic connection.
31st. The combination in time and space of all these thoughtful
conceptions exhibits not only thought, it shows also premeditation,
power, wisdom, greatness, prescience, omniscience, providence. In one
word, all these facts in their natural connection proclaim aloud the
One Cod, whom man may know, adore, and love; and Natural History must,
in good time, become the analysis of the thoughts of the Creator of the
Universe, as manifested in the animal and vegetable kingdoms.
It may appear strange that I should have included the preceding
disquisition in that part of my work which is headed Classification.
Yet, it has been done deliberately. In the beginning of this chapter, I
have already stated that Classification seems to me to rest upon too
narrow a foundation when it is chiefly based upon structure. Animals
are linked together as closely by their mode of development, by their
relative standing in their respective classes, by the order in which
they have made their appearance upon earth, by their geographical
distribution, and generally by their connection with the world in which
they live, as by their anatomy. All these relations should, therefore,
be fully expressed in a natural classification; and though structure
furnishes the most direct indication of some of these relations, always
appreciable under every circumstance, other considerations should not
be neglected, which may complete our insight into the general plan of
creation.
In characterizing the great branches of the animal kingdom, it is not
enough to indicate the plan of their structure, in all its
peculiarities; there are possibilities of execution which are at once
suggested to the exclusion of others, and which should also be
considered, and so fully analyzed, that the various modes in which such
a plan may be carried out shall at once be made apparent. The range and
character of the general homologies of each type should also be
illustrated, as well as the general conditions of existence of its
representatives. In characterizing classes, it ought to be shown why
such groups constitute a class and not merely an order, or a family;
and to do this satisfactorily, it is indispensable to trace the special
homologies of all the systems of organs which are developed in them. It
is not less important to ascertain the foundation of all the
subordinate divisions of each class; to know how they differ, what
constitutes orders, what families, what genera, and upon what
characteristics species are based in every natural division.
CHAPTER
II.
LEADING GROUPS OF THE EXISTING SYSTEMS OF ANIMALS.
SECTION 1. Great types or branches of the animal kingdom. 137
138
139
140
141
142
143
144
Attempt to define the
fundamental divisions of the animal kingdom.
Early classifications. Comparison of' the writings of different authors
with the view of determining what are natural groups among animals. The
great branches of the animal kingdom are characterized by the plan of
their structure. p. 137-144.
>Branches of the Animal Kingdom: Radiata, Molusca, Articulata,
Vertebrata
SECTION 2. Classes of animals. 145
146
147
148
149
150
Classes are natural
divisions,
characterized by the manner in which the plan of their respective great
types is executed, and by the means employed in the execution.
Structure considered in different points of view. p. 145-150.
[145] Structure may be considered from many points of view: first, with
reference to the plan adopted in framing it; secondly, with reference
to the work to be done by it, and to the ways and means employed in
building it up; thirdly, with reference to the degrees of perfection or
complication it exhibits; fourthly, with reference to the form of the
whole structure and its parts; fifthly, with reference to its last
finish, to the execution of the details in the individual parts.
[147] Classes of Radiata: Polypi - the body exhibits a large cavity
divided by radiating partitions into a number of chambers, into which
hangs a sac (the digestive cavity,) open below, whence it is circulated
to and fro in all the chambers, by the agency of cilia; Acalephs - the
body is plain and full not to be compared to a hollow sac, traversed
only in its thickness by radiating tubes, which arise from a central
cavity (the digestive cavity); Echinoderms - there is a tough or rigid
envelope to the body, inclosing a large cavity in which are contained a
variety of distinct systems of organs.
SECTION 3. Orders among animals. 150
151
152
153
154 155
Orders are natural groups
founded upon the degree of complication of the structure. Relative rank
or standing among animals. p. 150-155.
SECTION 4. Families. 155
156
157
158
159
160
161
Families are natural groups
founded upon the
form of animals. Indefinite use thus far made of the form in
characterizing animals. Importance of greater precision in that
respect. p. 155-161.
SECTION 5. Genera. Linnaeus' view of genera. Latreille. 161 162
163
Genera are natural groups
based upon the ultimate details of
structure. p. 161-163.
SECTION 6. Species. 163
164
165
166
167
168 169
170
Generally but wrongly based
upon fecundity. Hybridity, individuality, alternate generation,
polymorphism. Species
exist in nature in the same manner as any other natural groups; they
are based upon well determined relations of individuals to one another
and to the world around them, and upon the proportions, the
ornamentation, and the relations of their parts, p. 163-170.
SECTION 7. Other natural divisions among animals. 170
171
172
Besides branches,
classes, orders, families, genera, and species, which express the
fundamental categories of the existence of' animals, there occur here
and there further natural subdivisions, p. 170-172.
[170] Branches: plan of their structure; Classes: manner in which the
plan is executed; Orders: degrree of complication of the structure;
Family: Form of the structure; Genera: Details of execution of special
parts; Species: relation of individuals to one another and to the
environment, and proportions of their parts, ornamentation, etc.
Suclass: One system of organs has a peculiar development while other
systems coincide. (Marsupials contr. Placental Mammals).
SECTION 8. Successive development of characters. 172
173 174
175
176
In the
development of animals, the characteristic features do not appear in
the order of their systematic dignity. Their succession still requires
careful study. p. 172-176.
SECTION 9. Conclusions. 177
178
Classification is a
philosophical study of the greatest importance, p. 177-178.
CHAPTER
III.
NOTICE OF THE PRINCIPAL SYSTEMS OF
ZOÖLOGY.
SECTION 1. General remarks upon modern systems. 179
180
181
182 183
184
185
186
187
Their aim and
discrepancies. Desirable improvements. Limits of the fundamental
divisions with their respective classes. Rhiizopoda and infusoria.
Radiata, with three classes; Mollusks, with three classes; Articulata,
with three classes; Vertebrata, with eight classes. p. 179-187.
SECTION 2. Early attempts to classify animals. 187
188
189
Leading groups recognized
by Aristotle, p. 187-189.
SECTION 3. Period of Linnaeus. 189
190
191
192
Linnaeus was the first to
present
a definite system as expressing the natural affinities among animals,
p. 189-192.
SECTION 4. Period of Cuvier, and anatomical systems. 193
194 195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
Four types among
animals first recognized by Cuvier, p. 193. Classification of Cuvier,
p. 194. Irregularities of this system, p. l95. Classification of
Lamarck, p. 196. Its principle, p. 197. Classification of DeBlainville,
p. 198. Compared with those of Lamarck and Cuvier, p. 199.
Classification of Ehrenherg, p. 200. Its principle, p. 201.
Classification of Burmeistor, p. 203. Classification of Owen, p. 204.
Compared with those of Cuvier and von Siebold, p. 205. Growing
resemblance of modern systems, p. 206. Classification of Milne Edwards,
p. 207. Classification of von Siebold, and Stannius, p. 208.
Classification of Leuckart, p. 209. General
remarks upon anatomical classifications, p. 210.
SECTION 5. Physiophilosophical systems. Oken's views and
influence upon the progress of Zoölogy, p. 211. 211
212
213
214
215 216
217
218
219 220
His classification,
p. 212. Classification of Fitzinger, p. 214. Classification of McLeny,
p. 216. Affinity and analogy, p. 216-220.
SECTION 6. Embryological systems. 220
221
222
223
224
225
226
227 228
229
230
231
232
233
234
Influence of
Düllinger, p. 220. K. E. von Baer as systematic writer, p.
220-226. His classification, p. 226. Classification of Van Beneden, p.
227. Diagram
of the development of animals by Kölliker, p. 229. Classification
of
Vogt, p. 280. Further advance in perfecting the system of zoölogy
is
chiefly to be expected from embryological investigations.
PART
II.
NORTH AMERICAN TESTUDINATA.
CHAPTER I.
THE ORDER OF TESTUDINATA: ITS
RANK, CLASSIFICATION, AND GENERAL
CHARACTERS.
SECTION 1. Rank of the Testudinata. 235
236
237
238
239
240
The Testutlinata constitute
an
order in the class of Reptiles. The plan of structure of the
Vertebrata. Natural limits of the class of Reptiles. p. 235-240.
>Testudinata = Chelonians
SECTION 2. Special classification of Testudinata. 241
242
243
244
245
246
247
248
249
250
251
252
The
Testudinata constitute two sub-orders, which embrace several natural
families, p. 241-252.
SECTION 3. Essential characters of the order of Testudinata.
252
253
254
255
Their essential character
lies not so much in their shield, as in
the special development of the different regions of the body, which
assigns to them the highest rank in their class, p. 252-255.
SECTION 4. The Shield. 255
256
257
The shield consists of
parts of the true
skeleton, and of ossifications of the skin, or rather of the walls of
the body, which overlie the true skeleton, p. 255-257.
SECTION 5. The Skin. 257
258
259
260
261
262
263
264
265
266
The epidermis, p. 257. The
colors in Turtles, p. 261. The cerium, p. 263.
SECTION 6. The Skeleton. 266
267
268 269
270
Head, p. 266. Vertebrae, p.
266. Ribs, p. 267. Sternum, p. 267. Limbs, p. 267.
SECTION 7. The Muscles, p. 270. 270
271
272
273 274
SECTION 8. The Nervous System, p. 274. 274
275
276
277
SECTION 9. The Organs of the Senses. 277
278
The ear, p. 275. The eye,
p. 276. The nose, p. 276. The tongue and mouth, p. 277.
SECTION 10. Eating, Drinking, and Digestive Apparatus, p. 278. 278
279
280
281
SECTION 11. 7'he Respiration, p. 281. 281
282 283
284
285
Table showing the capacity
of the lungs compared with the weight of the body, p. 283.
SECTION 12. The Vascular System, p. 285. 285
286
287
SECTION 13. The Urogenital Organs. 287
288
289
290
Urinary organs. p. 287.
Genital organs, p. 287.
SECTION 14. The development of Turtles from a zoölogical point
of view, p. 290. 290
291
292
293
294 295
296
Table showing the
successive changes in the relative
dimensions of the body in Embridoidio, p. 292.
SECTION 15. The psychological development of Turtles compared with that
of the other orders of Reptiles. 296
297
298
299
300
301
Too little attention is now
paid to the faculties of animals, p. 296.
SECTION 16. Geographical distribution of the Testudinata.
301
302
303
Great discrepancy between
the range of marine Turtles compared with
that of the land and fresh water types, p. 301.
SECTION 17. First appearance of Testudinata upon
our globe, p. 303. 303
304
305
306
307
308
Table showing the period of
the first appearance of the
'Testudinata compared with that of the other
animals, p. 306.
SECTION 18. Suborders of Testudinata. 308
309
310
311
312
The suborders of sea
Turtles, Chelonii, p. 308. The suborder of fresh water and land
Turtles, Amydae, p. 310.
SECTION 19. Conclusions.
313
314
315 316
317
318
Ordinal characters are
essentially
anatomical characters, and not what are commonly called zoölogical
characters, p. 318.
CHAPTER
II.
THE FAMILIES OF TESTUDINATA.
SECTION 1. General remarks upon families. 318
319 320
The method generally
adopted in limiting families is defective. To arrive at satisfactory
results, it is necessary to ascertain by careful comparisons what are
the structural elements which constitute the different patterns of the
families. p. 318-320.
SECTION 2. The family of Sphargididae, p. 320. 320
321
322
323
324
SECTION 3. The family of Chelonioidae, p. 324. 324
325
326
327 328
329
SECTION 4. Tics family of Trionychidae, p. 329. 329
330
331
332
333
334
335
SECTION 5. The family of Chelyoidae, p. 335. 335
336
337
338
339
340
341
The Sternotheroidae,
Pelomedusae, Hydraspides, Chelodinoidae, and Podoenemides, note, p. 389.
SECTION 6. The family of Chelydroidae, p. 341. 341
342
343
344
SECTION 7. The family of Cinosternoidae, p. 344. 344
345
346
347
348
349
350
351
SECTION 8. The family of Emydoidae, p. 351. 351
352
353
354
355
356
Subfamilies: Nectomydoidae,
Deirocholyoidae, Evemydoidae, Clemmydoidae, Cistudinina, p. 355-356.
SECTION 9. The family of Testudinina, p. 356. 356
357
358
359
360
361
362
SECTION 10. On the brain of the different families of North American
Turtles.
The brain is typical for
different families among Vertebrata. p. 362. 362
363
364
365
SECTION 11. Differences in the mode of life of Testudinata. 365
366
367
The natural limits of
families do not always coincide with the mode of life of their
representatives. p. 365.
CHAPTER
III.
NORTH AMERICAN GENERA AND SPECIES OF
TESTUDINATA.
SECTION 1. General remarks upon the North American genera and species
of Testudinata. 367
368 369
370
371
How the genera of
Testudinata ought to be
characterized, and how they compare with genera in other classes, p.
367.
SECTION 2. The genus Sphargis, p. 371. 371
372
373 374
375
Sphargis coriacea, p. 373.
Identification and range of distribution of the species, p. 373.
SECTION 3. The genera and species of Chelonioidae, p. 375. 375
376
377
378
379
380
381
382 383
384
385
386
Chelonia, p. 877. Chelonia
Mydas, p. 378. Chelonia virgata, p. 379. Eretmochelys, p. 380. Eretmochelys
imbricata, p. 381. Eretmochelys squamata, p. 382.
Thalassochelys, p. 383. Thalassochelys Caouana, p. 384.
SECTION 4. Comparison of the growth of the Chelonii with that of the
Amyde, p. 386. 386
387
388
389
390
391
392
393
394
SECTION 5. The genera of Trionychidae, p. 394. 394 395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
Amyda, p. 898. Amyda
mutica, p. 399. Platypeltis, p. 400. Platypeltis ferox, p. 401.
Aspidonectes, p. 403. Aspidonectes spinifer, p. 403. Aspidonectes
asper, p. 405. Aspidonectes nuchalis, p. 406. Aspidonectes
Emoryi, p. 407.
SECTION 6. The genera of Chelonioidae, p.
410. 410
411
412
413
414
415 416
417
418
Gypochelys, p. 413. Gypochelys
lacertina, p. 414. Chelydra, p. 416. Chelydra serpentino, p. 417.
SECTION 7. The genera of Cinosternoidae, p. 418. 418
419 420
421
422
423
424
425
426
427 428
429
430
Sub-family of Ozothecoidae,
p. 423. Goniochelys, p. 423. Goniochelys triquctra, p.
423. Goniochelys minor, p. 424. Ozotheca, p. 424. Ozotheca
odorata, p. 425. Ozotheca tristycha, p. 425. Subfamily of
Cinosternoidae, p. 426.
Cinosternum, p. 426. Thyrosternum, p. 427. Thyrosternum
pennsylvanicum, p. 428. Thyrosternum sonoriense, p. 428. Thyrosternum
integrum, p. 429. Platythyra, p. 429. Platythyra flavescens, p. 430.
SECTION 8. The genera of Emydoidae, p. 430. 430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
Sub-family of
Nectemydoidae, p. 431. Ptychemys, p. 431. Ptychemys
rugosa, p. 431. Ptychemys concinna, p. 432. Ptychemys mobiliensis, p.
433. Ptychemys hieroglyphica, p. 434. Ptychemys decussata, p. 434.
Trachemys, p.434. Trachemys scabra, p. .134. Trachemys Troostii, p.
485. Trachemys elegans, p. 435. Trachemys rugosa, p. 436. Graptemys, p.
436. Graptemys geographica, p. 436. Graptemys LeSueurii, p.
436. Malacoclemmys, p. 437. Malacoclemmys palustris, p.
437. Chrysemys, p. 438. Chrysemys picta, p. 438. Chrysemys
marginata, p. 439, Chrysemys Bellii, p. 439,
Chrysemys Oregonensis, p. 440. Chrysemys
Dorsalis, p. 440. Sub-family of the Deirochelyoidae, p. 441.
Deirochelys reticulata, p. 441. Genera of the sub-family of
Evemydoidae, p. 441. Emys, p. 441. Emys meleagris, p. 442. Genera of
the Subfamily of Clemmydoidae. p. 442. Nanemys, p. 442, Nanemys
Guttata, p. 442. Calemys, p. 443. Calemys
Mühlenbergh, p. 443. Glyptemys, p. 443. Glyptemys insculita, p.
443. Actinemys, p. 444. Actinemys marmorata, p. 444. The sub-family of
Cistudinina. p. 444. Cistudo, p. 444. Cistudo virginea, p. 445. Cistudo
Triunguis, p. 445. Cistudo genata, p. 445, Cistudo major, p. 445.
SECTION 9. The Genera of Testudinina., p.
446. 446
447
448
449
Xerobates, p. 446. Xerobates ca
rolinus, p. 447. Xerobates berlandieri, p. 447,
Chelonoidis, p. 448. Megalochelys, p. 448.
SECTION 10. Chelonian Faunae of North America.
p. 449-450b. 449a 450b 451c 452d
The North-eastern Fauna p. 450b, The
Western Fauna. p. 450b. The Southern Fauna p. 451c. The Mexican
Fauna p. 452d. The California Fauna p. 452d.
VOLUME II
EMBRYOLOGY OF THE TURTLE
CONTENTS.
CHAPTER I.
DEVELOPMENT OF THE EGG FROM ITS FIRST APPEARANCE TO THE FORMATION OF
THE EMBRYO.
SECTION 1. The Origin of the Egg. p. 451. 451
452
453
454
455
456
457
458
SECTION 2. The Development of the
Yolk. p. 458 458
459
460
461
462
463
SECTION 3. The Development of the Yolk Cells. p. 463. 463
464
465
466
467
468 469
470
471
472
473 474
475
Formation of the Ectoblast.
p. 463. Formation of the Mesoblast. p. 467. Formation of the Ectoblast.
p. 472.
SECTION 4. The Purkinjean Vesicle. p. 475. 475
476
477
478
479
SECTION 5. The Growth of the Ovarian Egg, as a Whole. p.
479. 479
480
481
482
SECTION 6. The Graafian Follicle, and the Membranes of the
Egg. p. 482. 482 483
484
485
486
487
488
The Stroma. p. 482. The
Tunica granulosa. p. 483. The Zona pellucida. p. 484. The Vitelline
Sac. p. 485. The Embryonic Membrane. p. 486.
SECTION 7. Fecundation. p. 489. 489
490
491
492
493
494 495
496
497
498
CHAPTER
II.
DEVELOPMENT OF THE EMBRYO FROM THE TIME THE EGG LEAVES THE OVARY TO
THAT OF THE HATCHING OF THE YOUNG.
SECTION 1. The laying of the eggs. 498
499
500
501
Importance of local
information
respecting the habits of animals. The inhabitants of the country have
much knowledge upon this subject that is not yet recorded. Period of
laying. Passage of the eggs through the oviduct. Turtles lay only once
a year. p. 498-501.
SECTION 2. Deposition of the albumen and formation of the
shell. 501
502
503
504
505
506
507
508
509
510
The albumen and shell
membrane, p. 501-507. The shell, p. 508.
SECTION 3. The absorption of albumen into the yolk sac. 511
512
513
514
515
The albumen is gradually
absorbed into the yolk sac, p. 511-513. This
also takes place in birds' eggs, p. 513.
SECTION 4. The transformations of the yolk in the fecundated egg.
516
517
518
519 520
521
522
523
Enlargement of the
mesoblast, p. 516. Sudden multiplication of the entoblasts, p. 517.
Segmentation of the mesoblast, p. 517. It results in the formation of
the
primitive cellular basis of the germ, p. 522.
SECTION 5. Segmentation of the yolk. 523
524
525
526
527 528
The segmentation of the
yolk takes
place during the passage of the egg through the oviduct. The embryonic
disc and the germinal layer. p. 523-528.
SECTION 6. The whole egg is the embryo. 528
529
530
531
532
533
534
There is no natural limit
between the development of the embryo, from its first appearance as egg
to the formation of a distinct germ, and its ultimate growth.
Continuity of the genetic process, p. 528-534.
SECTION 7. Foldings of the embryonic disc, and successive stages of
growth q( the Turtle. 535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568 569
570
571
572
573 574
575
576
577
578
The embryonic disc, p. 535.
The
amnios, p. 536. Growth of the embryo, p. 542-578.
SECTION 8. Formation and development of the organs. 579
580
581
582 583
584
585
586
587
588
589
590
591
592
593
594 595
596
597
598
599
600
601
602
The brain, p. 579.
The ehorda dorsalis, p. 584. The eye, p. 584. The ear, p. 590. The
nostrils, p. 591. The vertebral column, p. 591. The skull, p. 592. The
shield, p. 592. The limbs, p. 593. The heart, p. 594. The bloodvessels,
p. 597. The intestine, p. 600.
SECTION 9. Histology. 602
603
604
605
606
607
608
609
610
611
612
613
614
615 616
617
618
The amnios, p. 602. The
spinal marrow, p. 602. The medulla oblongata, p. 602. The hemispheres,
p. 602.
The olfactory lobes, p. 608. The olfactory nerve, p. 603. The
Schneiderian membrane, p. 604. The pia mater, p. 604. The chorda
dorsalis, p. 604. The vertebrae, p. 605. The ribs, p. 606. The limbs,
p. 607. The skin, p. 608. The eye, p. 609. The ear, p. 611. The
intestine, p. 611. The allantois, p. 613. The urinary bladder, p. 614.
The lungs, p. 614. The trachea, p. 615. The liver, p. 615. The gall
cyst, p. 615. The bloodvessels, p. 615. The genital organs, p. 615. The
kidneys, p. 615. The Wolffian bodies, p. 616. The blood, p. 616. The
muscles, p. 617. The tendons, p. 618.
SECTION 10. Chronology of the development of the embryo. 618
619 620
621
622
From the first segmentation
of the yolk to the period of hatching, we
trace thirty-one stages of development, p. 618-622.
EXPLANATION OF THE PLATES, p. 623-640. 623
624
625
626
627 628
629
630
631
632
633
634
635
636
637
638
639
640
APPENDIX AND ERRATA, p. 641-643. 641
642
643
PLATES
