THE FUNCTION OF (ESTRIN 



117 



of oestrin into the immature guinea-pig, while Laqueur and de 

 Jongh (357) have caused growth in the uterus of the immature 

 dog.. 



The ancestrons animal. Asdell and Marshall (45) report the 

 induction of early procestrous changes in the anoestrous dog by 

 oestrin injection. Courrier (134) induced oestrous conditions in 

 the hibernating h'cdgehog by the same means. 



Dioestrus 



Normal oestrus 



Induced oestrus following' 



injection of oestrin 



Death 



lU Jays horizontal 

 scale 



Fig. 44. — Diagram showing the Growth Curves and CEstrous 

 Cycle Histories of Rats injected with CEstrin during 

 Vitamin B deficiency Ancestrus. 



Where ancestrus has been induced in the normal animal by 

 dietary deficiency, it is also possible to cause oestrous changes in 

 the accessory organs by injection of oestrin. Thus Parkes (497) 

 was able to bring about such changes during the anoestrous 

 periods caused by vitamin B deficiency. No ovarian stimulation 

 occurred. 



The dicestrotis or pseudo-pregnant animal. The dioestrous 

 interval of the rat and mouse is too short for accurate experi- 

 mental work to be done during this phase, but the dioestrous 

 phase in the accessory organs can be almost eliminated by 



