i84 MOSTLY MAMMALS 



the members of that group. Still, the whole character 

 of the dentition is so essentially rodent-like that there is 

 little wonder the old naturalists regarded the aye-aye as 

 a near relative of the squirrels. 



The general anatomy of the aye-aye, especially the 

 structure of its skull, shows, however, that it is certainly 

 a near relative of the lemurs, which are themselves distant 

 cousins of the monkeys, from which, among many other 

 peculiarities, they differ by their expressionless, fox-like 

 faces. The aye-aye is therefore classed as a lemuroid ; of 

 which group, owing to the peculiarity of its dentition and 

 its attenuated middle finger, it must be regarded as a highly 

 aberrant and specialised member. 



Unfortunately, in spite of recent explorations in the 

 superficial deposits of Madagascar, where bones of huge 

 extinct lemuroids have been disinterred, nothing whatever 

 is known as to the ancestry of the aye-aye. Evidently, 

 however, it must be a comparatively ancient type, for, if 

 we may judge from the analogy of other groups, a long 

 period of time must have been required to allow of the 

 gradual evolution and development of its characteristic 

 peculiarities of dental and manual structure. 



Evidently these peculiarities must be connected with its 

 mode of life. And we learn from those who have observed 

 the creature in its native forests or in captivity, that the 

 aye-aye, unlike the true lemurs, subsists largely upon wood- 

 boring insect larvae, especially on the larva of a beetle known 

 to the Malagasy by the name of andraitra. Apparently the 

 aye-aye possesses a sense of hearing so acute that when 

 on a bough it can hear the faint rasping sound made by 

 the jaws of the andraita as it bores its way through the 

 wood in the interior. Thereupon it at once sets to work 

 with its powerful front teeth to chisel away the intervening 



