§ I EXAMINATION OF BITTERLING HYPOPHYSIS 



49 



basophil 



chromophobe acidophil 



m 



IVt". 



Fig. 44B. Showing the change of acidophile cells of the gonadotrophic 

 pituitary zone into basophils and back again into acidophile cells. 



We shall now examine more closely the cellular changes 

 in the gonadotrophic region. 



The resting-stage of the gonadotrophic cells of the anterior 

 lobe is characterized, in the control-animal, by acidophilia 

 (Fig. 44B). Shortly after the first exogenous stimulus the 

 cells suddenly turn markedly basophilic. After some time, 

 however, they revert to acidophilia. It would seem from this 

 that the intermediate basophil stage is probably the actual 

 working phase of the cell and represents the restitution phase 

 of the product, i.e., the luteinisation hormone. Without 

 further study of the finer cytological changes we may, on the 

 basis of colour differentation, present the following pro- 

 visional survey of the process:— 



1. Accumulation stage. The cells are homogeneously 

 filled with an acidophil secretion. 



2. Extrusion stage. Inter-cellular acidophil secretions 

 occur in the form of drops. 



! 3. Restitution stage. 



a. The emptied cell remains about the same size, and, 

 owing to its very slight affinity for stains, is 

 chromophobe; 



b. The cells are diffuse, but coloured distinctly 

 basophil; 



