E. Y. COWDRY 





or different* stages of cytomorphosis. Our information concerning the 

 conditions in man is especially unsatisfactory. 



Secretory Antecedents. Many consider the doubly refractile lipoid 

 granules to be true secretion antecedents, but evidence is illusive. Da Costa 

 is of the opinion that the mitochondria are changed into lipoid, which is 

 somewhat similar to Mulon's view, according to which the mitochondria, 

 themselves are the secretion antecedents of a lipoid substance which com- 

 pletely impregnates the cells (dark cells) and passes through the inter- 

 cellular spaces into the blood vessels. He thinks that the interstitial cells 



of the testis and ovary 

 likewise produce a lipoid 

 secretion. This interpre^ 

 tation is supported by the 

 presence of an abundance 

 of lipoid in all three, and 

 by the fact that they are 

 all developed from the 

 nearby cells of the Wolffian 

 ridge. The interstitial 

 cells of the ovary are, how- 

 ever, said to be more easily 

 destroyed by X-rays than 

 those of the testis. The 

 suprarenal cortex contains 

 cholin, but it is unlikely 

 that this constitutes a 

 specific secretion. 



The Medulla. Cytol- 

 ogy. The epithelial cells 

 of the medulla (Fig. 8) 

 are arranged in a very ir- 

 regular fashion in columns 

 and clusters, surrounded 

 with loose connective tis- 

 sue, blood vessels, nerves, 

 and lymphatics. They are 



in very intimate association with the venous sinusoids. The cells do not 

 differ very much inter se. Definite types are not distinguishable as in 

 the cortex. There are no structural indications of a division of labor in 

 the different regions of the medulla. The internal architecture of the 

 cells has been very carefully investigated in mammals. They contain 

 numerous mitochondria and, occasionally, pigment and fat also. The 

 nuclei are spherical and often somewhat larger than those of the cor- 

 tical cells. A careful study of the reticular apparatus is much needed. 



A 



Fig. 7. Cortex of human suprarenal gland show- 

 ing the very intimate relation of the cells to the blood 

 vessels and the vacuolated condition of the cytoplasm 

 caused by the solution of the lipoid droplets (mag- 

 nification 720). 



