PROFESSOR OWEN ON THE AYE-AYE. 45 
limbs is nearly black, with a little admixture of white-tipped hairs at their thick 
beginning. 
The tail shows no habitual twist or bend, but hangs straight from the trunk in the 
dead animal’. It is flexible in all directions, and the long, coarse, slightly wavy hairs 
grow equally from it all round: most are nearly black, but reflect a rufous tint in some 
lights, through admixture of hairs that retain that colour at the base. The penis, 
unerect, projects about an inch from the pubis ; of a subconical form, with a terminal 
transverse orifice of the prepuce, which is of a whitish colour. The testes make slight 
prominences below and at the sides of the penis (Pl. XVI.). 
From the foregoing description we may infer that the small quadruped is arboreal, 
the limbs being organized chiefly for grasping ; and this power is given in the greater 
degree to the hind feet, as in all climbers. The wide circle of the ‘ open eye’ or fully 
expanded eyelids, the large iris, and the pupil reducible to a minute point when the 
iris is contracted, indicate a climber of nocturnal habits’. The development of the 
organ of hearing bespeaks the acute possession of that sense. The chief office of the 
tail may be inferred to be that of adding to the protective non-conducting covering of 
the body when the animal is in repose. in taking this attitude, Dr. Vinson states that 
the Aye-aye depresses the head between the fore paws, bends over it the tail, which is 
for that purpose depressed and curved forward ; then, slowly rolling its body into a 
ball, covers the whole by the outspread hairs of the encircling tail®. Thus Dr. Vinson’s 
animal slept the greater part of the day, moving about and making its efforts to escape 
during the night. Having once succeeded, it climbed the nearest tree and moved about, 
leaping from branch to branch with the agility of the Lemur catta ; but its ordinary life 
in captivity suggested the idea of its being an indolent and rather slow-moving animal. 
Its cry is a plaintive grunt‘. 
§ 3. Skeleton (Pls. XIX.-XXL.). 
The bones of the Aye-aye have a compact texture, and, although the specimen was 
transmitted in spirits, they show, after a short maceration, a pure white colour. The 
number of vertebrz between the skull and sacrum is twenty-six, of which thirteen are 
dorsal, six lumbar, and seven cervical. The sacral vertebrae are two by anchylosis 
and connexion with the ilia, but three by antero-posteriorly extended and co-articu- 
lated transverse processes; the caudal vertebre are, accordingly, twenty-three or 
twenty-two,—the sum-total of vertebra being fifty-one, exclusive of the four cranial. 
The true vertebre describe one slight curve convex backward from the middle 
* [In the living female the tail is usually carried in a curve, concave downward.—August 1862.] 
* [The pupil is widely open at dusk, when the animal is most active ; it contracts to asmall circle by day, in 
the living female.—August 1862.] 
* [The female, now in captivity, shows the same use and disposition of the tail, in repose. —August 1862. ] 
* Comptes Rendus de I’Acad. des Sciences, Paris, 22 Octobre, 1855. 
