THE CONDITIOXS OF LIFE IK ANIMA TED BEINGS. 



423 



and brandies of trees. Often these trees have 

 fissures, and it is possible to reach the larvte which 

 bore them, and pull them out from their holes ; 

 but the openings, being narrow, allow only a very 

 slender instrument to pass. The aye-aye has its 

 taper finger for an instrument. The animal must 

 necessarily have at its disposal senses, au in- 

 stinct, an intelligence, fit to lead it to the de- 

 signed object. In fact, it has eyes with an ex- 

 tremely dilatable pupil, which amply admits the 

 faint twilight or moonlight, and allows it to roam 

 the forests at night without the least difficulty. 

 It has ears that indicate great delicacy of hear- 

 ing, and beyond doubt it detects the slight noise 

 made by the larvae in gnawing the wood. It 

 brings an astonishing intelligence to the demands 

 of its pursuit ; it may be seen striking a trunk 

 or branch of a tree with its nail — in a word, 

 availing itself of percussion to learn whether a 

 hollow exists that may contain a grub. Possess- 

 ing a keen scent, the aye-aye satisfies itself of the 

 quality of its food. Dr. Vinson, to whom we owe 

 interesting observations on the animals of the 

 island of Madagascar, relates that an aye-aye in 

 captivity would not accept all grubs indifferently, 

 and distinguished between them by smelling. This 

 curious mammal, related to the makis by its gen- 

 eral characteristics, has a dental system similar 

 to that of gnawing animals. Fond of those trop- 

 ical fruits that are full of savory pulp, it bites 

 through their hard shell with its strong incisors, 

 introduces its slender finger through the open- 

 ing thus made, and, bringing its mouth near the 

 orifice, draws the pulpy substance out. When 

 one hand is tired it uses the other. 



Can we find a creiture better fitted for living 

 in conditions strictly determined, or correspond- 

 ing more completely in singularity of habits with 

 its singularities of conformation ? The famous 

 English naturalist, Richard Owen, author of an 

 excellent essay on the chiromys of Madagascar, 

 finds in it strong arguments in refutation of ideas 

 too readily accepted as to the mutability of spe- 

 cies. By its zoological characteristics, the aye- 

 aye is an isolated being in creation ; like the 

 makis, its nearest relatives, it inhabits forests in 

 which insects everywhere abound. Nothing would 

 compel it, any more than other animals of the 

 same group, to prefer those kinds that are hidden 

 in the trunks of trees, unless a peculiar distinc- 

 tion, related to peculiar instincts and organs, had 

 been assigned to it from the beginning. Is there 

 the least reason to suppose that the tapering of 

 one finger on the fore-extremities has been pro- 

 duced through a forced use by individuals in a 



succession of generations, when they had no need 

 of subjecting themselves to that trouble to find 

 food in abundance ? 



The digging animals, intended for an under- 

 ground life, are well known in respect to their 

 characters and instincts, which are in a manner 

 repeated in the most different types. Every one 

 notices their body, tolerably long and nearly cy- 

 lindrical, their short, broad, and extremely power- 

 ful fore-limbs. Observe the mole : its body pre- 

 sents no prominent part capable of obstructing 

 easy circulation in narrow galleries ; its fore-feet 

 resemble strong hands, with the palm turned out- 

 ward, and with broad, sharp nails. Could one 

 imagine instruments more perfectly adapted to 

 break up and push away the earth ? The ani- 

 mal's muzzle, made resistant by the presence of 

 a special bone, is a snout, acting like a gimlet. 

 To these peculiarities, which explain the mole's 

 manner of life so well, are added senses devel- 

 oped to a degree that corresponds with the con- 

 ditions of existence of this mammal. Organs of 

 sight are useless to a being condemned to live in 

 darkness ; and these are rudimentary. A very 

 delicate touch is indispensable to their recogni- 

 tion of each other in their dark abodes ; it is given 

 by the muzzle, which is nearly bare, having some 

 stiff, scattered hairs. In a contracted space, to 

 be warned of a danger, or of the presence of in- 

 sects that form its prey, it is important that it 

 should be sensitive to the least sounds; its organs 

 of hearing answer that requirement. In the ab- 

 sence of sight, a very keen sense of smell is of the 

 first necessity, to guide it in the search for food ; 

 and its olfactory organ is greatly developed. An 

 organization and instincts so well adapted to an 

 underground life make existence impossible for 

 the mole in any other conditions. 



In a certain insect there are found peculiari- 

 ties of form, habits, and instincts, so similar to 

 those of the mole, that the insect, after the pop- 

 ular idea, has been called the mole-cricket. It 

 has an almost cylindrical body, its fore-claws 

 pressed close toward the head, with legs prodig- 

 iously large, and provided with strong serrations, 

 so as to bear a kind of resemblance to the feet 

 of the mole. The legs of the mole-cricket and 

 the feet of the mole are organs of entirely differ- 

 ent nature, marked by an almost identical adap- 

 tation. 



There are animals which, among those of the 

 same class or family, present nothing more unu- 

 sual than some particularity which seems to be 

 trifling. "When the reason for this insignificant 

 peculiarity is found, a strong interest arises. 



