19G MAMMALIAN DESCENT. [LECT. VIII. 



unchanged descendants of any type from which the 

 Primates sprang ; yet the latter, higher, forms may 

 have arisen from old and more generalised Lemuroids. 

 It is just possible that the peculiar isomorphism, or 

 similarity in outer form, of these types with the 

 Monkeys may have deceived us, and have suggested 

 a nearer relationship than really exists. That that modi- 

 fication of the inner digit on both the mamis and pes, 

 hand and foot, which makes these organs capable of 

 grasping, should be seen in both Monkeys and Lemurs, 

 is a strong suggestion of affinity, and yet may not be 

 due to any near relationship. I am inclined to put the 

 two groups nearer together than Professor Flower would ; 

 but, as I have only lately begun to work at the Lemurs, 

 I am rather doubtful and cautious. Yet the skull and 

 teeth, as well as the hands and feet, are very similar in 

 both cases, and I feel satisfied that the Primates did 

 arise from archaic Lemuroids. The fact that the 

 Lemuroid types found in the Tertiary deposits are un- 

 distinguishable from Carnivores, on the one hand, and 

 from the most archaic Herbivora, on the other, shows 

 how difficult classification becomes, when we pass 

 into palaeontology. These problems ask for help from 

 embryology ; the early conditions of the groups already 

 brought under review, also those of the Lemuroids, as 

 well as the Tapir and the Hyrax, the most generalised 

 types of existing Herbivora, will throw new light upon 

 this question. I hope to do something towards this 



