POPULAR SCIENCE 83 



may be a trifling loss, but it is a variation, nevertheless, in 

 the wrong direction as regards survival. It is difficult to 

 believe that the offspring of Palaeopithecus or of any large ape 

 of the Pliocene could have varied in three directions, and yet 

 have ever afterwards bred true in regard to such basal parts 

 of the skeleton as the ribs and spine ; and to add to the 

 enigma. Flower and Lydekker regard the brain of the orang 

 as being nearest to that of man. 



Reconstruction — The Lower Eocene 



Starting with a generahsed primate of the Anaptomorphus 

 type, we have an animal about as large as a rat. It had a large 

 brain and very large eyes. It is inferred that this animal lived 

 in the trees and had clasping feet, perhaps with partially 

 opposable thumbs. What part of the tree did it frequent and 

 what was its object in going to the trees ? An opposable thumb 

 as part of a very small hand is seen in some marsupial forms 

 not much larger than a rat. These live during the night on 

 the small twigs and branches amongst the leaves, where the 

 diameter of the part of the plant supporting them is small 

 enough to be at least partially encircled by the hand. As the 

 large eyes indicate nocturnal habits, this proto-primate may 

 have caught and eaten birds roosting in the small branches. 

 As it depended on sight and not on scent, the moonlight made 

 the difference between full and scanty supplies of food. Hence 

 the monthly cycle was established in the female, and this has 

 persisted in all the descendants of this proto-primate, including 

 the lemurs. The effect of special food has been stamped on 

 all these animals. 



Some other inferences become probable. Anaptomorphus 

 has small and even teeth and a short face. This type of face 

 has persisted in some South American monkeys, and it is easier 

 to picture a short nose and muzzle growing long than the 

 opposite trend of development. For instance, in the case of 

 dogs the breeds with a very short muzzle appear to be rather 

 at a disadvantage. The general type of the alimentary canal 

 in the primates is another important point. This more re- 

 sembles that of the carnivora than that of the herbivora, and 

 the size and structure of each type is related to the percentage 

 of nitrogen in the food-supply. The proto-primate therefore 

 secured a diet rich in nitrogen, almost like a carnivore, and 

 the normal pattern of the hand and foot suggest that the diet 

 was not insects, spiders, and grubs, for if these were the original 

 food of the arboreal primates one should expect to see many 

 modifications of the teeth and fingers similar to those found 



