OOPHORECTOMY AND THE PITUITARY 45 



there is an increased invasion of the pars nervosa by Author's 

 cells from the pars intermedia. Stionof 



It is most important, too, in experimental work not staining 

 to lose sight of the fact that the phases of secretory pars anterior. 

 activity vary in different orders of animals and at 

 different ages in the same animal, and that the large 

 basophil cells and basophil 'colloid' are not seen, so 

 far as my experience goes, either at all or with the same 

 regularity in the various species of rodents, as in the 

 higher mammals. 



Further, it must be mentioned that the pars inter- 

 media secretes a granular ' colloid ', normally basophil 

 in reaction, but in some circumstances, to be mentioned 

 directly, eosinophil. 



The ' colloid ' which is formed both in the pars 

 anterior and in the pars intermedia is probably a storage 

 secretion, like the colloid seen in the thyroid. The most 

 active method of secretion in both parts of the pituitary 

 is intracellular. In the actively secreting pars inter- 

 media the cells swell up and become fused, and the 

 secretion is, I believe, for the most part taken up 

 immediately by the blood or lymph. Nevertheless, 

 some of the masses of secretion which may be seen in 

 the pars intermedia, and even the actual cells, pass 

 directly into the pars nervosa, whence absorption occurs ; 

 and it is in the pars nervosa that, as already stated, the 

 pressor qualities of infundibulin are acquired. 



To return from this necessary digression. Removal Hyperplasia 

 of the ovaries appears to cause a certain increase in the anterior 

 secretory activity of the anterior lobe of the pituitary follows 

 body on the lines indicated ; but in my experience the tomy. 

 change is moderate and not quite constant. Thus in one 

 experiment cat no. 5 of the ovarian removal series 

 recorded above after an interval of 208 days there was 

 no divergence from the normal to be recognized histo- 

 logically. 



The effect appears to be more or less temporary, 

 and in no way comparable with the genital lesions seen 

 after partial extirpation of the pituitary. In most of 



