VIII.] 



HOMOLOGIES. 



179 



Homology may be further distinguished into (1) a rela- 

 tionship which, on evolutionary principles, would be due 

 to descent from a common ancestor, as the homological 



TARSAL BONES OP DIFFERENT LEMTTROIDS. 



ig ht-hand figure, Tarsus of Galago ; left-Jumd figure, Tarsus of Cheirogaleus.) 



relation between the arm-bone of the horse and that of the 

 ox, or between the singular ankle-bones of the two lemurine 

 genera, cheirogaleus and galago, and which relation has 



