DEPARTMENT OF EMBRYOLOGY. 



85 



Based on the 704 normal specimens selected from om' collection, the 

 mean weight and sitting height for the end of each week of menstrual 

 age, from the eighth week to term, are given in table 1, together with 

 the actual and percentage weekly increments. The 704 specimens 

 included 252 white males, 241 white females, 66 negro males, 60 negro 

 females; other races, males, 15; females, 11; unidentified as to race or 

 sex, 59. 



Table 1. — Menstrual age with mean sitting-height and weight. 



It is of interest to note from this table that the increment in height 

 is greatest from the thirteenth to the seventeenth week, reaching a 

 maximum of 1 5 mm. at the sixteenth week. Throughout the remainder 

 of the fetal period the weekly increase is surprisingly constant, varying 

 between 9 and 11 mm. The relation of the increment in height to the 

 actual height of the specimen shows, however, a steadily decreasing 

 percentage. The increment in weight, in contrast to the increment in 

 height, is a constantly increasing one. The percentage increment in 



