164 EVOLUTION AND DISEASE. 
the thoracic, and the third pair in the inguinal region 
(fig. 86). It is said, but I have had no opportunity of 
verifying the statement, that Zarszus spectrum has an 
inguinal and a pectoral pair of milk-glands; the aye- 
aye (Chetromys) has only an inguinal pair; lastly, the 
Fic. 86.—A Dwarf Lemur (A/7crocebus smithi), showing the 
arrangement of the mammary glands. 
gray, or broad-nosed lemur (//apalemur griseus), has the 
mammary glands situated on its arms.! 
The above facts (with the exception of those relating 
to Hapalemur) seem to indicate that the lemurs have 
descended from ancestors possessing two rows of 
mamme. In the dwarf lemurs, the abdominal pair 
* Beddard, “ Proc. Zool. Soc.” 
