1 64 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 Tarsius spectrum has an 

 inguinal and a pectoral pair of milk-glands ; the aye- 

 aye (Cheiromys) has only an inguinal pair ; lastly, the 



FIG. 86. A Dwarf Lemur (Microcebus smithi), showing the 

 arrangement of the mammary glands. 



gray, or broad-nosed lemur (Hapalemur grisens], has the 

 mammary glands situated on its arms. 1 



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 

 mammse. In the dwarf lemurs, the abdominal pair 



1 Beddard, "[Proc. Zool. Soc." 



