Fig. 1. Newborn rats; left, control; Fig. 2. Rat embryos removed on the 20th day 

 right, offspring of an STH-treated of gestation. Left , control ; right , embryo of 

 mother. STH-treated mother. 



Fig. 3. Above: left to right, embryos of control rats at the 20th, 19th and 

 18th days of gestation; below: two 20-day embryos removed from STH- 

 treated mothers. 



facing page 162 



