THE TARSIER AND THE AYE-AYE 241 



small parties are found singly or in pairs. They are looked upon with great dread 

 and horror by the native inhabitants of the Malayan islands. According to the late 

 Mr. Gumming, who once had a female and young tarsier alive, the animal is known 

 to the natives of the above-mentioned islands by the name of the Malmag. The 

 same writer also informs us that only one young is produced at a birth ; and that 

 when the natives capture one of a pair, they are sure of securing its fellow. When 

 feeding, the tarsier sits up on its hind-quarters and holds its food in its hands, 

 somewhat after the fashion of a squirrel. 



THE A YE- AYE {Chiromys madagascariensis) 



The last of the lemur-like animals, and, at the same time, of the whole order 

 of Primates, is the aye-aye of Madagascar, which has teeth so utterly different from 

 all other members of the order that it was long considered to belong to the Rodent 

 order (rats, rabbits, etc.). 



The most peculiar feature about the teeth of the fully adult aye-aye is that the 

 front, or incisor teeth, are reduced to a single pair in each jaw, which are curved, 

 and have their extremities brought to a sharp chisel-like edge, admirably adapted 

 for gnawing and rasping hard substances. The structure of these teeth is in fact 

 precisely the same as in the front teeth of rats and beavers ; their sharp, cutting- 

 edge being produced by the circumstance that while the body of the tooth is formed 

 of the comparatively soft ivory, the front surface is faced with a layer of hard, flinty 

 enamel. And it will be obvious that the result of wear in a tooth of this type will 

 be to produce a chisel-like edge. It will further be apparent that such a tooth, 

 if continually employed in rasping away hard substances, would be very quickly 

 worn away altogether, if it were of the same length as ordinary teeth, and not pro- 

 vided with some kind of renewal. This difficulty is obviated by the front teeth of 

 the aye-aye remaining open at their lower ends, and undergoing a continual process 

 of growth ; so that as their summits are worn away they are pushed further up 

 from below. In all these points their teeth are precisely similar to those of the 

 Rodent Mammals. A further resemblance to Rodents is shown by the absence of 

 tusks in the aye-aye ; and also by the cheek-teeth being separated by a long gap 

 from the incisors, as well as by being reduced in number, and having their crowns 

 with nearly flat surfaces, instead of being surmounted with the sharp cusps found 

 in those of the true lemur. Indeed, the total number of teeth in the adult aye-aye 

 is only eighteen; these being expressed by the formula i\, c, p\, m\, or exactly 

 the same as in many Rodents. 



If, then, the teeth of the adult aye-aye are so exactly like those of a Rodent, 

 the reader may well ask why it is not placed among the rats and beavers, instead of 

 among the lemurs. To this it may be replied that in the young aye-aye the milk- 

 or baby-teeth are very much more like those of the true lemurs ; while the anatomy 

 of the skeleton and the soft parts is essentially that of a lemur, and not that of a 

 Rodent. The resemblance of the skull and teeth of the aye-aye to those of a 

 Rodent, is, indeed, an excellent instance of what zoologists term an adaptive or 

 parallel resemblance. When two animals belonging to totally different groups have 

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