50 



HYPOPHYSIS^-O VARY -> OVIPOSITOR 



II 



c. Ring-shaped formations occur in their plasma, 

 resembling GOLGI-systems, together with granu- 

 losa coloured a deep blue; 



d. In addition to the decreasing number of granules, 

 numerous light vacuoles occur; 



e. Basophilia grows weaker and gradually gives place 

 to acidophilia. Side by side with basophil granules, 

 and vacuoles occur in the plasm. 



4. Transition. The cell finally becomes homogeneously 

 acidophil again. The rings and granules arising during the 

 working phase might therefore be regarded as a product pre- 

 ceding the luteinisation hormone, the acidophil granules and 

 vacuoles, and, finally, the diffuse, extruded drops constituting 

 the actual incretion. Cellular activity fluctuates between these 

 two working phases since the first secretion of hormones is 

 followed by a restitution, and when this is finished and the 

 organ is stimulated afresh, another yield ensues; in other 

 words a rhythm is created. 



These rhythmic fluctuations were determined as follows. The hypo- 

 physeal sections were projected on to a sheet of paper 35 X 25 cm. The 

 basophil cells were traced (Fig. 45). The islands were blackened with 

 marking ink, and the blackened area measured in relation to the remain- 

 ing quantity of white. 



We used an instrument which indicates, by means of two thermal 

 elements and a galvanometer, under a constant amount of light, the degree 

 of blackening as a galvanometer reading. In order to obviate errors arising 

 through possible fluctuation in the intensity of the light, a calibrated scale 





% 









Fig. 45. Basophile cell-islands in the gonadotrophic zone; respectively 

 o, 15, 30 mins. and 1, 8, 10 hours after administration of progesterone. 



