Age Factor in Some Prenatal Endocrine Events 23 



of the gland (Cohen, 1954). Decapitation introduces a striking 

 underdevelopment of the cortex (see Jost, 1954). A reduction 

 in size of the cortex and some shrinkage of the cells occurs at 

 birth (Josimovich, Ladman and Deane, 1954); alteration in the 

 lipid content was observed by Miss Cohen (1955, unpublished 

 data) in a few foetuses which had not been delivered at 22J 

 days of age. It might be wondered whether such changes 

 are correlated with a reduction in the adrenocorticotrophic 

 activity of the pituitary gland at the time of birth. 



Glycogen storage in the liver 



It is almost a hundred years since the discovery by Claude 

 Bernard that the foetal liver stores appreciable amounts 



t ~ 23 tk 25 26 27 28 23 



Days 



Fig. 1. Liver glycogen content expressed in mg./g. of fresh tissue; 

 black points represent control foetuses; crosses represent foetuses 

 decapitated between days 19 and 24 and killed on days 26 to 28; triangle 

 represents foetuses decapitated on day 26 and killed on day 29. 



of glycogen from a certain stage onwards when suddenly 

 accumulation begins. In the rabbit foetus the turning- 

 point appears on day twenty-five (Lochhead and Cramer, 

 1908, and Fig. 1). Although the question has not yet been 



