240 LEMURS. 



animal is known to the natives of the above-mentioned islands bj- 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 secuiing 

 its fellow. When feeding, the tarsier sits up on its hind-quarters and holds its 

 fooil in its hands, somewhat after the fashion of a squirrel. 



The Aye-Aye {Chiromys maduguscariensis). 



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

 of Primates, is the aj^e-aye of Madagascar, which has teeth so uttei-ly different 

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

 Rodent oixler (rats, rabbits, etc.). 



The most peculiar feature about the teeth uf 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, admirabljr 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 liard substances, would ])e very (juickly worn away 

 altogether, if it were of the same length as ordinary' teeth, and not provided with 

 some kind of renewal. This difficulty is obviated by the front teeth of the aye-aye 

 r'emaining open at their lower ends, ami inidergoing 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 furtlier 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 

 ti'ue lemur. Indeed, the total number of teeth in the adult aye-aye is only 

 eighteen; these being expressed by the formula i\, c{}, ^:)J, ■ni|, or exactly the same 

 as in many Rodents. 



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

 the reader may well ask why it is not placed among the rats and beaver.S, 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 essentiallj' 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 more or less nearly similar habits, it frequently results that they will closely 

 resemble one another in at least some part of their structure ; such particular 

 structure being the one best adapted for a particular mode of life. In all such 

 cases a supei-ficial examination of the animals in question will frequently lead to 



