CLASSIFICATION OF THE ANIMAL KINGDOM. 
13 
Thus, the working bees, from the crcntion of the world, have always 
constructed edifices of great ingenuity, upon principles deduced from the 
highest branches of geometry, for the purpose of lodging and nourishing 
a posterity which is not even their own. 
“ It is a curious mntlicmatical problem,” observes Dr Reid, “ at wbat precise 
angle three planes which compose the bottom of a cell in a honey-comb ought to meet, 
in order to make the greatest saving, or the least expense, of material and labour; 
and this i.s the very angle in which the three planes in the bottom of a cpll do actually 
meet. Shall we a.sk here, w'ho taught the bee the properties of solids, and to resolve 
the problems of maxima and minima i tVe need not say that bees know none of these 
things. They work most geometrically, somewhat like a child, who, by turning the 
handle of an organ, makes good music, without any knowledge of music. The art is 
not in the child, but in Hiai who made the organ. In like manner, when a bee makes 
its comb so geometrically, the geometry is not in the bee, but iu that Great Geometri- 
cian who made the bee, and made all things in number, weight, and measure.” 
The solitary bees and wasps construct very complicated nests for the 
reception of their eggs. From each egg there proceeds a worm which has 
never seen its mother, which knows not the structure of the prison en- 
closing it; and yet, after it has undergone its metamorphosis, will con- 
struct another nest, precisely similar, to contain its own egg. 
No satisfactory explanation can be given of the phenomena of instinct, 
except we admit that these animals pos.scss some innate and constant 
internal power, which determines them to act, in the same manner as 
when they arc influenced by ordinary and accidental sensations. Instinct 
haunts them like a perpetual reverie or vision ; and all the actions pro- 
ceeding therefrom may be compared to those of a man walking in his 
sleep. 
Instinct has been wisely bestowed upon animals by the Creator, to 
supply the defects of their understandings, the want of bodily force or 
fecundity; and thus the continuation of each species is secured to the 
proper extent. 
There is no visible mark, in the conformation of an animal, by which 
we can ascertain the degree of instinct which it possesses. But so far as 
observation has hitherto extended, the degree of intelligence seems pro- 
portioned to the relative size of the brain, and especially of its hemis- 
pheres. 
Without venturing to decide upon this point, we must remark that the latter asser- 
tion has been controverted by many recent observers, especially by Dr Herbert hlayo, 
in his valuable Outlines of Human Physiology. “ It does not appear," he remarks, 
that an iucrea.ee in the absolute weight of the brain confers a superiority in mental 
endowments. Were this the case, the intellects of the whale and of the elophant 
should excel the rational nature of man. Neither does the relative weight of the 
brain to the whole body appear the measime of mental superiority. The weight of 
fbe human brain is but one thirty-fifth part, while that of a canary bird is one-four- 
teenth part. Nor in conjunction with parity of form, and strueture even, does this 
relation appear of .any value. The eagle is probably as sagacious as the canary bird; 
but the weight of the brain is but one two-hundred-and-sixticth part of its entire 
Weight. 
“ We may next inquire,” he proceeds, ‘‘ whether au increasing number and eompli- 
cation in the parts of the brain is essentially connected with improved mental func- 
tions. The first instances which occur to the mind are in favour of the alHrmative of 
this supposition. It may bo inferred, from their docility and surprising capability of 
receiving instruction, that birds have higher mental endowments than fish ; and ae- 
vordingly, in place of tlio nodules of the fishes’ brain, whioh arc scarcely more than 
tubercles to originate nerves, birds possess an ample cerebrum and cerebellum (or lobes 
®f their bruin). But iu pursuing this argument, if we compare, on the other hand, 
the brain of birds with those of alligators and tortoises, we find no striking ditforonco 
tw physical superiority in the former over the latter ; yet in mental development, the 
tortoise and alligator are probably much nearer to fish than to birds. The instunlia 
^’ucis (or decisive experiment), however, upon this question, is found in the compimi- 
®on of the brain of the cotaceous mammalia (such as whales or dolphins), with the 
luman brain on tho one hand, and with that of fish on the opposite. 
The cetaceous mammalia,” he observes, “ have brains which, besides being of 
go size, ore nearly as complicated as those of human beings ; they might therefore 
lari 
be 
expected, if tho opinion which I am combating were true, to manifest a remarkable 
^iid distingijishing degree of sagacity. Endowed with a brain approaching nearly in 
rtimploxity and relative size to that of man, the dolphin should resemble in his habits 
“be of the transformed personages in eastern fable, who continued to betray, under 
b brute disgtdse, his human endowments. Somclliing there should be, very marked 
‘b bis deportment, which should stamp his essential diversity from the fishes, in whose 
general mould ho is cast. His habits too, not shunning human society, render him 
especially open to observation ; and the class of moo vvho have the constant opportunity 
Watching his gambols in the deep, are famed for their credulity, and delight to 
boli 
‘eve in the mermaid, tho, sea-snake, and tho kraken. Yet the 
m.oriner sees no- 
','bg in the porjioiso or the dolphin but a fish, nor di.stinguishcs him, except by his un- 
wieldy hulk, from the shoal of herrings he pursues. Tho dolphin shows, in truth, no 
bgacity or instinct above the carp, or the trout, or tho salmon. It is probable even 
b the latter, which have but the poore.st rudiment of a brain, greatly exceed him 
bbnning and sagacity. 1 am afraid that the instance which I have laSt adduced 
sufficient to ovortlirow most of the rceeivod opinions respecting the relation of the 
^ “b, shape, and organization of the brain to mental development ; nor is it easy to find 
besting-place for conjecture upon this subject.” 
SECT, vm ON THE CLASSIFICATION OF THE ANIMAL KINGDOM. 
General Distrihulion of the Animal Kingdom into Four Great Divisions. 
1. Vertebrata — 2. Moltusca — 3. Articuiata — 4. liadiata. 
After the observations which have already been made concerning sys- 
tems of cla.ssification in general, we have now' to ascertain those leading 
characters of animals, upon which we must found tlie primary divisions 
of the Animal Kingdom. It is evident tliat these must he derived from 
the animal functions, tliat is, from sensation and motion ; for not only do 
tliese functions constitute tliem animals, but they point out tlie rank 
whicli they hold in the aiiinud world. 
Observation confirms the correctness of this ro.asoning, hj' showing tliat 
their development and intricacy of .structure correspond in degree with 
tliose of tho organ.5 performing tlie vegetative functions. 
Tile heart and tlie organs of circulation form a kind of centre for the vege- 
tative functions, in tlie same manner as tlie brain and the trunk of tlie ner- 
vous system are the centres of the animal functions; for we see these two 
systems become gradually more imperfect, and finally disappear together. 
In the very lowest classes of animals, where nerves can no longer be dis- 
covered, all traces of muscular fibres are obliterated, and the organs of 
digestion are simply excavated in tlie uniform mass of their bodies. The 
vascular system [or systematic arrangement of vessels] in insects, disap- 
jiears even before the nervous ; but, in general, the medullary masses arc 
dispersed in a degree corresponding to the agents of muscular motion. A 
spin.al marrow, on which are various knots or ganglions, representing so 
many brains, corresponds exactly to a body divided into numerous annu- 
lar [or riiig-like] segments, supported upon pairs of limbs, distributed along 
its entire length. 
Tin's general agreement in tlie construction of animal bodies, resulting 
from the arrangement of their organs of motion, the distribution of the 
nervous masses, and the energy of tho circulating system, ought, then, 
to form the Itasis of the primary divisions of the Animal Kingdom. We 
shall now proceed to examine what the characters are, which ought to 
succeed immediately to the above, and give rise to tlie first subdivisions. 
If we divest ourselves of the popular prejudices in favor of long estab- 
lished divisions, and consider the Animal Kingdom upon the principles 
already laid down, without reference to the size of the animals, their uti- 
lity, the greater or less knowledge we may have of them, or to any of 
these accidental circumstances, but solely in reference to their organiza- 
tion and general nature, we sliall find that there are four principal 
forms, or (if wo may use the c.xpression) four general plans, upon which 
all animals appear to have been modelled. The minor subdivisions, by 
whatever titles they maybe ornamented by Naturalists, are merely slight 
modifications of those great divisions, founded upon the greater develop- 
ment or addition of some parts, while the general plan remains essentially 
the same. 
1. Vertebrata — Vertebrated Animals. 
In the first of these forms, which is that of Man, and of the animals most 
resembling him, the brain and the principal trunk of the nervous system 
are enveloped in a bony covering, composed of the cranium [or skull], and 
the vertebra; [or bone.s of the neck, hack, and loins.] To the sides of this 
medial column are attached tlie ribs, and tlie bones of the limbs, forming 
collectively tlie framework of tlie body. Tlie muscles, in general, enclose 
the bones which they set in motion, and the viscera are contained within 
the head and trunk. 
Animals possessed of this form are called Vertebrated Animals (Ani- 
malia vertebrata), [from their possessing a vertebral column, or spine.] 
They are all supplied with rod blood, a muscular heart, a mouth with 
two jaws, one being placed either above or before the other, distinct or- 
gans of sight, hearing, smell, and taste, iu the cavities of the face, and 
never more than four limbs. The sexes are always separate, and tho 
general distribution of the medullary masses, M'ith the principal branches 
of the nervous system, are nearly tlie same iu all. 
Upon examining attentively eacli of tlie parts of tliis extensive division 
of animals, we shall always discover some analogy among them, even in 
species apparently the most removed from each otlior; and the leading 
features of one uniform plan may be traced from man to tlie lowest of the 
fishes. 
The following are examples of Vertebrateil Animals: Man, quadrupeds, whales, 
birds, serpents, frogs, tortoises, herrings, carps, &c. 
2. Mollusca — Alolhiscous Animals. 
In the second form of animals wo find no skeleton. Tho muscles are at- 
tached solely to the skin, which forms a soft envelope, capable of con- 
4 
