CLASSIFICATION OF THE ANIMAL KINGDOM. 



13 



Thus, the working bees, from the creation 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 mathematical problem," observes Dr Reid, " at what 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 is the very angle in which the three planes in the bottom of a cell do actually 

 meet. Shall we ask here, who taught the bee the properties of solids, and to resolve 

 tlie problems of maxima and minima ? We 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 him who made the organ. In like manner, when a bee makes - 

 its comb so geometrically, the geometry is not in the bee, but in 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, preciselj' similar, to contain its own egg. 



No satisfactory explanation can be given of the phenomena of instinct, 

 e.xcept we admit that these animals possess some innate and constant 

 ■internal power, which determines them to act, in the same manner as 

 when they are 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 wliich 

 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 IMavo, 

 in his valuable Outhnos of Human Physiology. ** It does not appear," he remarks, 

 ** that an increase 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 elephant 

 should excel the rational nature of m.in. Neither does the relative weiglit of the 

 brain to the whole body appear the measure of mental superiority. The weight of 

 the human brain is but one thirty-fifth part, while that of a canary bird is one-four- 

 teenth part. Nor iu conjunction with parity of form, and structure even, does this 

 relation appear of any value. The eagle is probably as sagacious as the canary birdi 

 but the weight of the brain is but one two-hunJred-and-si.xlieth pai't of its entire 

 weight. . 



" We may nest inquire," he proceeds, " whether an increasing number and compli- 

 cation in the parts of the brain is essentially connected with improved mental func- 

 tions. The first instances v.'hich occur to the mind are in favour of the affirmative of 

 this supposition. It may be inferred, from their dociUty and surprising capability of 

 receiving instruction, that birds have higher mental endowments than fish ; and ac- 

 cordingly, in place of the nodules of the fishes' brain, which are scarcely more than 

 tubercles to originate nerves, birds possess an ample cerebrum and cerebellum (or lobes 

 of their brain). But in pursuing this ai-gument, if we compare, on the other hand, 

 the brain of birds with those of alligators and tortoises, we find no striking difference 

 or physical superiority iu the former over the latter; yet in mental development, the 

 tortoise and alligator are probably much nearer to fish than to birds. The instantia 

 crucis (or decisive experiment), however, upon this question, is found in the compari- 

 son of the brain of the cetaceous mammalia (such as whales or dolphins), with the 

 human brain on the one hand, and with that of fish on the opposite. 



" The cetaceous mammalia," he observes, " have brains which, besides being of 

 large size, are nearly as complicated as those of human beings ; they might therefore 

 be expected, if the opinion which I am combating were true, to manifest a remarkable 

 and distingiiisliing degree of sagacity. Endowed with a brain approaching nearly in 

 complexity and relative size to that of man, the dolphin should resemble iu his habits 

 one of the transformed personages in eastern fable, who continued to betray, under 

 a brute disguise, his human endowments. Something there should be, very marked 

 in his deportment, which should stamp his essential diversity from the fishes, in whose 

 general mould he is cast. His habits too, not shunning human society, render him 

 especially open to observation ; and the class of men who have the constant opportunity 

 of watching his gambols in the deep, are famed for their credulity, and delight to 

 beheve in the mermaid, the sea snake, and the kraken. Yet the mariner sees no- 

 thing in the porpoise or the dolphin but a fish, nor distinguishes him, except by his un- 

 wieldy bulk, from the shoal of herrings ho pursues. The dolphin shows, in truth, no. 

 sagacity or instinct above the carp, or the trout, or the salmon. It is probable even 

 that the latter, which have but the poorest rudiment of a brain, greatly exceed him 

 in cunning and sagacity. I am afraid that the instance which I have last adduced 

 is sufficient to overthrow most of the received opinions respecting the relation of the 

 si2e, shape, and organization of the brain to mcutal development; nor is it easy tc find 

 a resting-place for conjecture upon this subject." 



SECT. VIII ON THE CLASSIFICATION OF THE ANIMAL KINGDOM. 



General Distrihution of the Animal Kingdom into Four Great Divisions. 

 1. Vertelrata — 2. MoHusca — 3. Jrticulata — 4. Radiata. 



After the observations which have already been made concerning sys- 

 tems of classification in general, we have now to ascertain those leading 

 characters of animals, upon which we must found the primary divisions 

 of the Animal Kingdom. It is evident that these must be derived from 

 the animal functions, that is, from sensation and motion ; for not only do 

 these functions constitute them animals, but they point out the rank 

 which they hold in the animal world. 



Observation confirms the correctness of this reasoning, by showing that 

 their development and intricacy of structure correspond in degree with 

 those of the organs performing the vegetative functions. 



The heart and the organs of circulation form a kind of centre for the vege- 

 tative functions, in the same manner as the brain and the trunk of the 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 ver}' 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 the uniform mass of their bodies. The 

 vascular system [or systematic arrangement of vessels] in insects, disap- 

 pears even before the nervous ; but, in general, the medullary masses are 

 dispersed in a degree corresponding to the agents of muscular motion. A 

 spinal marrow, on which are various knots or ganglions, representing so 

 many brains, corresponds exactly to a body divided into numerous annu- 

 lar [or ring-like] segments, supported upon pairs of limbs, distributed along 

 its entire length. 



This general agreement in the construction of animal bodies, resulting 

 from the arrangement of their organs of motion, the distribution of the 

 nervous masses, and the energy of the circulating system, ought, then, 

 to form the basis 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 the 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, tlieir 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 shall find that there are four principal 

 forms, or (if we may use the expression) four general plans, upon whiclt 

 all animals appear to have been modelled. The minor subdivisions, by 

 whatever titles they may be ornamented by Naturalists, are merely slight 

 modifications of these great divisions, founded upon the greater develop- 

 ment or addition of some parts, while the general plan remains essentially 

 the same. 



1. Vektebkata — -Vcrtcbratcd 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 vertebra3 [or bones of the neck, back, and loins.] To the sides of tliis 

 medial column are attached the ribs, and the bones of the Umbs, forming 

 collectively the framework of the body. The muscles, in general, enclose 

 the bones which they set in motion, and tlie 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 supphed with red 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, in the cavities of the face, and 

 never more than four hmbs. The sexes are always separate, and the 

 general distribution of the medullary masses, with the principal branches 

 of the nervous system, are nearly the same in all. 



Upon examining attentively each of the parts of this extensive division 

 of animals, we shall always discover some analogy among them, even in 

 species apparently the most removed from each other; and the leading 

 features of one uniform plan may be traced from man to the lowest of the 

 fishes. 



The following are examples of Vertebrated Animals : Man, quadrupeds, whales, 

 birds, serpents, frogs, tortoises, herrmgs, carps, &c. 



2. MoLLUscA — Molluscous Animals. 



In the second form of animals we find no skeleton. The muscles are at- 

 tached solely to the skin, which forms a soft envelope, capable of con- 



