XVII ANATOMY OF THE AYE-AYE 549 
attention may be called to the long and bushy tail, to the greater 
length of the hind-limbs, to the abdominal teats (one pair) in the 
female, and above all to the singular third digit of the hand, 
which is thin and elongated. The thumb is, as in other Lemurs, 
opposable, and has a flat nail; the remaining digits have claws, 
as have also the toes with the exception of the great toe, which 
has a flat nail like the thumb. 
The anatomy of this animal has occupied the attention of a 
considerable number of observers, dating from Sir R. Owen, who 
was the first to give a connected account of its entire organisa- 
tion. The most recent paper of importance is by Dr. Oudemans.’ 
The teeth are very unlike those of other Lemurs. The most 
remarkable divergence is in the incisors, which are present to 
the number of but a single pair in each jaw, and are shaped 
like those of the Rodentia, and in the same way as in that 
group grow from persistent pulps. There are likewise, as in 
the Rodents, no canines. There are two premolars in the 
upper jaw (none in the lower) and altogether twelve molars, so 
that there is a total of eighteen teeth. The intestine has a 
moderately long caecum. The brain has been most fully described 
by Oudemans, who had fresh material to work with, the brain 
described by Owen having been extracted from a spirit-preserved 
carcase. The angular fissure is well developed, as in Lemur and 
the Indri; but it does not join the infero-frontal. The antero- 
temporal fissure is also well developed. 
“The name of Aye-aye,” wrote Sonnerat, the discoverer of the 
animal, “which I have retained for it, is a cry of surprise of the 
inhabitants of Madagascar.” It is, however, usually said that 
the animal itself makes a sound which may be written in the 
same way (or with an initial H). It is an arboreal and 
nocturnal animal, which accounts for its excessive rarity at one 
time. In one of his many eloquent essays upon natural history 
the late Mr. P. H. Gosse adduced the Aye-aye as an example of 
a creature on the verge of extinction. It is, however, now more 
frequently met with, though the superstition of the natives 
renders its capture a matter of some difficulty. There is a 
specimen at the moment of writing in the Zoological Society's 
Gardens. There has been some discussion as to the use of the 
slender middle finger: it is stated that it can thrust it into the 
1 Verh, Ak. Amsterdam, xxvii. 1890. 
