ANIMAL. 



145 



wanting in numerous and extensive classes, and 

 it varies conspicuously in the members of every 

 tribe among which it is apparent. In his in- 

 tellectual powers man is not less eminently 

 raised above all the other beings of creation 

 than in his moral constitution : he alone takes 

 note of the phenomena that pass around him 

 with ulterior views, and he alone perceives the 

 relation between effect and cause, preparing 

 and foreseeing consequences long before they 

 happen. 



Locomotion is a function so evidently in re- 

 lation with the circumstances surrounded by 

 which animals exist, and with the apparatus by 

 which it is accomplished, that it is enough to 

 refer back to the structure for proof and illustra- 

 tion of its infinite modifications among the 

 various genera and species of the animal king- 

 dom. Some, by their constitution, are inca- 

 pable of motion from place to place, but they 

 still perform those partial motions which their 

 preservation as individuals require taking their 

 food, respiring, voiding their excretions, &c. 

 Those that can move from one place to another 

 have organs in relation to the mode in which 

 this motion is accomplished, whether it be by 

 creeping, by swimming, by running, leaping, 

 flying, Sec. &c. Every partial movement ex- 

 ecuted by the higher animals has, farther, its 

 own special apparatus : the intestinal canal has 

 its muscular parietes; the necessity that is felt 

 to communicate internal sensations and ideas 

 has its pathognomonic means in the looks, 

 gestures, sounds of the voice, and so on. 



Nor is it only in the greater or less degree of 

 complexity of their general structure, in the num- 

 ber and diversity of their particular organs, or in 

 those of the actions whose sum constitutes their 

 vitality,that animals differ from one another; they 

 vary farther in the degree in which these organs 

 and these functions are enchained or mutually 

 dependent. In the most simple animals so 

 complete is the independence of the several 

 parts, that their bodies may be divided into 

 numerous pieces without injury to the vitality 

 of any one of them, each possessing in itself 

 the capacity to commence a separate existence. 

 In animals somewhat more elevated in the scale 

 we observe very extensive powers of reproduc- 

 tion at least, of parts that have been lost, and even 

 of continuing existence in very insignificant 

 remainders of their bodies. In the most ele- 

 vated tribes, however, the dependence of every 

 part upon the whole becomes such that neither 

 will the body essentially mutilated survive, nor 

 will any part of the slightest consequence con- 

 tinue to live. Among the beings at the bottom 

 of the scale we have in fact found the organiza- 

 tion to be homogeneous, or without distinction 

 of parts, and nutrition to be accomplished by 

 means of an immediate absorption and exhala- 

 tion; and as every part possesses the structure 

 which makes it capable of these two acts, every 

 part, it is evident, suffices for its own existence. 

 In the higher classes of animal existence, how- 

 ever, nutrition requires the concurrence of a mul- 

 titude of peculiar acts ; and in order that life may 

 be continued in any fragment of one of the mem- 

 bers of these, it is plain that this fragment must 



vor. i. 



contain the organs of every one of the functions 

 essential to nutrition. Further, it is certain that 

 the nervous system, when once it has fairly made 

 its appearance, strictly dominates the nutritive 

 function, and that every part of the nervous 

 system itself becomes progressively more and 

 more dependent on one of its portions, the 

 encephalon or brain, as animals stand higher in 

 the scale of creation, and as the functions over 

 which the nervous parts preside respectively 

 are themselves of a higher order. These are 

 new and additional reasons for the centraliza- 

 tion of life, or for the complete dependence of 

 the organs and their functions one upon another 

 among the more perfect animals man, the 

 quadrumans and quadrupeds, birds, &c. 



So much for the acts that minister to the 

 preservation of the individual. Let us now turn 

 to the interesting series by which species are 

 continued. In the very lowest grades this end 

 is accomplished without the concurrence of 

 sexes : at a determinate period of its life the 

 animal either separates into several fragments, 

 which become so many new and independent 

 individuals, or it throws out a number of buds 

 or germs from its external surface or from a 

 particular internal cavity. The first of these 

 modes of reproduction is entitled fissiparous, 

 the second external gemmiparous, and the third 

 internal gemmiparous. 



When we examine animals in the next grade, 

 we find reproduction taking place by the con- 

 currence of sexes, or rather of two kinds of 

 organs which we afterwards discover divided 

 between different individuals, who are then 

 said to be of opposite sexes. When the male 

 and female organs are united in the same indi- 

 vidual it is denominated an hermaphrodite ani- 

 mal, and in some cases seems to suffice for its 

 own impregnation ; more generally, however, 

 hermaphrodite animals are not capable of per- 

 forming this act upon themselves, but require 

 the concurrence of another individual of similar 

 constitution: the two hermaphrodites meet and 

 severally impregnate one another. 



Among the more perfect classes of the ani- 

 mal kingdom the organs of reproduction are 

 universally allotted to two different individuals, 

 males and females, which consequently become 

 in their dualism representatives of their species. 

 Agreeing in this single feature, the modifica- 

 tions in the process of reproduction are never- 

 theless extremely numerous. In some cases 

 the fecundating fluid of the male is only ap- 

 plied to the egg or germ of the female after its 

 extrusion from her body, as happens among 

 fishes, several reptiles, &c.; in others the male 

 fluid is injected into the body of the female, 

 and made to fecundate the germ still attached 

 to its parent. This act is generally, though not 

 invariably, accomplished by means of a penis, 

 or male external organ, with which many birds 

 and all the animals above them in the scale of 

 animal creation are then provided. 



With this contact or intermixture of bodies 

 we have the following varieties in the after-parts 

 of the process : the egg or germ now fecun- 

 dated is either forthwith expelled from the 

 body, and it is only subsequently, under the in- 



