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cranial cavity appears in these two individuals. This is mainly the 

 resnlt of the circumstance tliat the little skull of the Orang child 

 was so much younger than that of the Gorilla child. With this 



Fig. 6. 



Fig. 7. 

 very young Orang the orbit is still entirely enclosed by the cranial 

 cavity, the whole roof of the orbit is here still tlie floor of the 

 anterior cranial cavity. In (he adult Orang the orbit has come much 

 more forward. So here also a considerable forward shifting has taken 

 place. In orang this was not accompanied by the formation of a 

 ridge as in Gorilla, firstly because the orbits and in particular their 

 roof did not advance so far before the cranial cavity, and secondly 

 because the anterior cranial wall in Orang had thickened evenly. 

 The changes in the topographical relations with Chimpanzee 

 appears when we compare figures 8 and 9. With this genus the 

 forward shifting is smaller again than with Orang, although still 

 considerable. The projection in fig. 8 has been taken from a little 

 skull with complete milk-dentition, that of fig. 9 from an adult skull. 



