Influence of STH and Cortisone on Foetal Growth 167 



is increased during gestation. Moreover, the author believes 

 that the foetal gigantism which occurs in certain pathological 

 conditions, notably with diabetic and pre-diabetic mothers, 

 could be brought about by a somatotrophic hypersecretion of 

 the maternal pituitary. 



However, the somatotrophic hypersecretion in the pregnant 

 female, postulated by Young and often accepted by clinicians, 

 has not been demonstrable. The results of our experiments 

 make the suggestion that the influence of STH is the cause of 

 foetal gigantism, hardly credible. Moreover, the fact that 

 maternal hypophysectomy does not inhibit foetal develop- 

 ment also shows that embyronic growth is not pituitary- 

 controlled. This interpretation is supported by the fact that 

 the destruction or ablation of the foetal pituitary (Raynaud 

 and Friley, 1947; .Tost, 1947) does not appear to slow down 

 foetal growth in the mouse or rabbit. It also links up with 

 clinical observations on the children of acromegalic mothers. 

 Neither Jackson (1954) nor Huant (1955) have observed the 

 stigma of gigantism in the children of acromegalic mothers; 

 in one case, Huant even noted signs of marasmus and under- 

 development. 



Thus these experimental results and clinical observations 

 confirm each other and that somatotrophic hormone does not 

 enter into the embryonic development of mammals. 



Nevertheless, the inhibition of the embryonic growth of 

 the rat, which we observed with early administration of STH 

 and which is probably indirectly caused, is worthy of our 

 attention, for the possibility of consistently obtaining embryos 

 of more juvenile appearance may provide an interesting 

 method of studying the metabolic factors conditioning em- 

 bryonic growth. 



Cortisone 



The inhibition of embryonic growth by somatotrophic 

 hormone led us to examine the influence of another hormone, 

 cortisone. It is remarkable that whilst somatotrophic hormone 



