DESCRIPTION OF PLATES 



The photographs from which the plates were made were all taken during the 

 fourth week. 



Plate I. The carrying position. The attitude of the monkeys in this photo- 

 graph is not quite typical of the carrying position. Dolly has stopped and 

 the baby is preparing to drop to the ground. He is consequently somewhat 

 farther from Dolly's body than is usual. 



