130 



C. M. Jackson. 



respond to approximately 48 per cent of the total volume by my 

 method. Between birth and adult life the trunk therefore apparently 

 increases slightly in relative size. 



%- 



Days of Gestation 



Fig. 2. Curves showing relative prenatal growth of the various parts of the 

 body, in specimens studied, the size being expressed in percentage of the total 

 body volume (Table IV). The dotted lines at the right represent the postnatal 

 growth of the corresponding parts (based on data from Meeh). 



The Extremities. 



The extremities are seen to be at first relatively very s.mali, each 

 forming between 2 per cent and 3 per cent of the total body volume 

 during the 2d month. The upper extremities are usually slightly 

 larger than the lower until early in the 3d month. Then both begin 

 to increase in relative size, the lower more rapidly. The increase in 

 the relative size of the extremities during the first half of the fetal 

 period counterbalances the relative decrease of the head and trunk 

 during that period, as shown by the curves in Fig. 2. In the second 



