CHARACTERS OF THE LEMURS AND TARSIUS. 



27 



to scent them. Bat so far as my observations go, this action is 

 restricted to the male when stimulated to anger at the time 

 of rut. 



Also in Lemur catta, but in no other species referred to the 

 genus, there is a large gland in the male on the inner side of 

 the upper arm near the top of the biceps muscle just below the 

 shoulder (text-fig. 3, C). It is a circular or elliptical mound-like 

 elevation covered with short hair, except in the centre of the 

 summit where there is a small naked area carrying , the orifice of 

 the gland which is usually shaped like a strongly curved crescent. 

 In section the gland is seen to be composed of a thick-walled 

 sac, the cavity of which is subdivided by ridges and outgrowths 

 of the walls, making, in a sense, a multilocular gland. It is the 

 partial blocking of the rounded orifice of the gland by one of 

 these outgrowths that gives the orifice its crescentic shape. The 

 cavity of the gland is filled with strong-smelling brown sticky 

 secretion which under pressure can be squeezed, like a worm, 

 from the orifice (text-fig. 3, D, E). 



In the female this gland is not always developed, and when 

 present it consists of a small elevation covered with normally long 

 hair and having no cavity or trace of orifice (text-fig. 3, F). 



The suggestion that these glands are modified mamma ry glands 

 is, I think, erroneous. At all events they coexist with the normal 

 pectoral mammary glands. 



It is interesting to recall that Hapalemur also has a similar 

 gland on the shoulder and a, somewhat similar gland above the 

 wrist. I have, however, seen these only on dried skins, and have 

 nothing to add to the descriptions published by Beddard * and 

 Bland- Sutton f. 



But there are two points worth attention arising out of the 

 facts just mentioned. Despite the development of these glands 

 in Lemur catta and Hapalemur griseus, and in no other species, 

 these two Lemurs do not appear to be nearly related. Judging 

 from cranial and dental characters, the relationship of Hapalemur 

 griseus is with Prolemur smuts, and of Lemur catta with the 

 other species usually assigned to the genus Lemur. 



The second point is the coexistence in two otherwise dissimilar 

 genera of two sets of glands, one below the shoulder, the other 

 above the wrist. This raises the very important question of 

 possible correlation in development between two or more struc- 

 tures, a question which opens a very wide field for research in 

 zoology. 



The Hands and Feet. 



In the species of Lemur the digits of the hand are longish and 

 slender, and free from webbing to approximately the same extent 

 as in Man. The pollex is the shortest of the series and is sepa- 

 rated by a wide space from the second, the base of which it 



* Proc. Zool. Soc. 1884, p. 393 ; and 1891, p. 450. 

 f Proc. Zool. Soc. 1887, p. 369. 



