146 



M A M MALI A. 



perfectly stable. It seems, however, that for general 

 purposes a line is requisite, in order to ensure this 

 stability. No doubt, as we see in figurantes and pos- 

 ture-masters, the body may be so educated as to be 

 balanced on a single point ; but then, during such 

 balancing, it is good for nothing as respects any other 

 kind of action, and would of course be of no use in 

 the natural economy of any animal. The same kind 

 of stability may also be obtained by pirouetting or 

 whirling round on the one toe, in which the body is 

 kept up by centrifugal force, just as a top is kept up 

 in the motion of spinning ; but this again occupies 

 the whole of the powers and the attention, and could 

 not be any portion of the natural movement of 

 an animal, in whatever manner that animal were 

 organised. 



With the exception of man, none of the mammalia 

 possesses a line of stability in the foot, whatever may 

 be the form of that foot ; for though there are many 

 animals which walk on the tarsus, the ankle joint has 

 no support backwards, unless there is a heel bone, 

 which none of them possess. An ape, therefore, in 

 common with the rest, has a yielding basal line, and not a 

 stable one in each of the hind feet ; and therefore, 

 though many of the species can stand up, they are 

 always tottering, incapable of much action in the 

 erect posture, wriggling in their attempts to walk, 

 and very speedily tired. The chimpansee is perhaps 

 the best walker among them, because its limbs are 

 shorter in proportion, and thus they have not so much 

 lever power in their flexures ; but still it cannot pro- 

 ceed far without calling in the assistance of the 

 fore legs. 



But, besides the short base between the articula- 

 tions of the thigh bones, and the very imperfect basal 

 lines furnished by the feet, the climbing structure of 

 the hind feet of apes gives them other disqualifications 

 for walking. The joints of the thigh bones are loose, 

 in order to allow a great deal of motion upon the 

 foot which holds on, while the anterior part of the 

 animal is engaged farther up among the branches. 

 The knee joint also has a far more rolling motion 

 than is consistent with steady walking, and therefore, 

 the march of an ape, whether attempted on the hind 

 legs only, or performed upon all fours, has not the 

 firm tread, nor does it show any of the more elegant 

 paces either of a biped or a quadruped. That very 

 flexibility of its legs, and also their length, enable it 

 to leap with great agility, and, generally speaking, 

 with agility greater in proportion as its legs are less 

 adapted for walking. This is common in all verte- 

 brated animals which have long, ungainly, and folded 

 hind legs, as we may see in the frog, whose leap is 

 longer in proportion to the size of the animal than 

 that of a stag or a greyhound ; but nobody ever saw 

 a frog walking. It is something the same with the 

 apes, and it may be stated as a general truth, that the 

 longer their legs are, they are the more agile leapers 

 and the less capable of walking. Hence we see thai 

 in proportion as the limbs of those animals are better 

 organised for one particular species of action, they 

 are worse fitted for every other. 



This is a very important principle in the study o 

 the animal economy. It not only shows us that the 

 supply of resource in every animal is so nicely adapte( 

 to the animal's. necessity for that resource, that ther 

 is neither waste nor want, but a perfect sufficiencj 

 joined to an equally perfect economy. It shows u 

 farther, that in studying the structure and economy 



f any animal, or of any well-arranged group of anl- 

 lals, we have only one general character to study, 

 rhich, when fully understood, carries us readily and 

 riefly through all the details. Were it not for this 

 ast circumstance a knowledge of natural history would 

 ie altogether beyond the ability of the most zealous 

 nd long-lived member of the human race, because 

 he acquired knowledge would never afford a means 

 f arriving at the knowledge sought ; and we should 

 lave the old simile of the bundle of rods with the band 

 roken, and the strength dependent upon unity gone. 



The larger apes of the south-east of Asia are 

 lerhaps still better organised for climbing than the 

 jhimpansee, and in proportion as they are better 

 dapted for that they are less so for walking. They 

 are more exclusively forest animals, and march among 

 he branches with so much rapidity that it requires a 

 olerably swift animal to keep pace with them on the 

 ground below. Their anterior extremities are exceed- 

 ngly lengthened, and thus they can extend their 

 rasp to long distances in proportion to their size and 

 weight. The great extent to which their legs fold 

 without any straining of the joints, and the circum- 

 itance of their fore paws reaching the ground when 

 he spine is not very greatly depressed from the hori- 

 :ontal position, enables them to spring from all four 

 at once ; and thus, when pursued upon the ground 

 3y enemies, if they can get near a tree they can spring 

 and seize a branch at a considerable elevation. They, 

 and indeed almost all the apes of the eastern conti- 

 nent, can also rest their limbs by reposing in a sitting 

 posture, and embracing the tree with one limb. They 

 are enabled to do this for a greater length of time 

 than almost any other animal could, in consequence 

 of the pads of callous and elastic matter with which 

 the posterior parts of the body are provided ; and 

 though their habits during sleep are not much known, 

 it is probable that many of them repose in the trees 

 in this position. 



The baboons are perhaps not so exclusively tree 

 animals as the apes, but are more on the ground, and 

 more habitually upon all fours. They climb well, but 

 they do not leap with so much agility as the long- 

 limbed foresters ; they are therefore exposed to more 

 danger from ground enemies, and therefore nature has 

 given them more surly dispositions, and more power- 

 ful weapons of defence, in tneir long and strong canine 

 teeth. We may remark that, though the teeth of the 

 apes bear a very considerable resemblance to those 

 of man, and that the baboons, notwithstanding their 

 large canines, have no carnivorous cheek-teeth, yet. 

 that the whole of the race, even down to those of 

 comparatively small size, have very powerful action 

 of the jaws and bite desperately, more severely even 

 than carnivorous animals of the same size and weight, 

 though their bite is a cutting and not a tearing one. 

 This strength of the jaws, and power of bite, are 

 closely connected with the climbing character of the 

 animals ; for many of the fruits upon which they 

 subsist are enclosed in such hard external coverings, 

 that great force is required in order to get at the part 

 fit for nourishment. 



The very numerous species and genera of quadru- 

 mana of the eastern continent, known by the common 

 but ill-defined name of monkeys, all climb nearly in 

 the same manner as the apes, and being more slender 

 in their bodies, and thus capable of inhabiting smaller 

 twigs, they are more frequently seen. They are, 

 generally speaking, better walkers than the others, 



