38o 



HELEN DEAN KING. 



In Table II. are given the data for cases in which the number 

 of young suckled was five or less while the number of young in 

 the second litter exceeded five. 



TABLE II. 



In eight of the eleven cases shown in Table II. the period of 

 gestation was prolonged from one to six days. In the three 

 remaining cases the gestation period was normal since it did 

 not exceed 23 days. These results indicate that, as a rule, the 

 period of gestation is prolonged when a lactating female, suckling 

 a small number of young, is carrying a litter containing six or 

 more embryos. 



Table III. shows the length of the period of gestation in 

 lactating females suckling more than five young. 



TABLE III. 



Since in the twelve cases recorded in Table III. the period of 

 gestation ranged from a minimum of 25 days to a maximum of 



