244 R. R. HUMPHREY 



dissolved either wholly or in part. The lipoids of the degener- 

 ating lobules do not (except for a short time immediately after the 

 emptying of the lobule) reduce potassium dichromate sufficiently 

 to be preserved by modified Zenker techniciue, which demon- 

 strates the interstitial cell lipoids, though without preserving 

 perfectly the form of the droplets. After staining with copper 

 or iron hematoxylin, material thus fixed shows the degenerating 

 lobules entirely unstained while the interstitial cells are deeply 

 colored, due to their chromated lipoids. 



No chemical analyses of the testis were made by the wTiter, but 

 from the characteristics of these lipoids it may safely be assumed 

 that they are similar to the phosphatid lipoids and cholesterin- 

 esters described by Whitehead ('12), Hanes ('11), and other 

 workers as occurring in the interstitial cells of mammals. 



Neither intracellular masses of secretion product (other than 

 the fuchsinophile granules and lipoid droplets already described) 

 nor accumulations of such a product in spaces between cells have 

 been encountered in my material. Such intercellular accumula- 

 tions have been reported by Lenhossek ('97) for man, Senat 

 ('00) for the rat, Bouin and Ancel ('03, '04) for the fetal horse, 

 and Duesberg ('18) for the opossum. Duesberg describes an 

 intercellular space filled with a secretion substance from which 

 he could see, on the one hand, processes extending back into 

 adjacent cells and, on the other hand, a connection with a small 

 capillary. This is surely, as he says, ''one of the clearest instances 

 in which the secretion product of a gland with internal secre- 

 tion actually could be followed from the gandular cell into the 

 vascular system." Had there been present in Necturus such 

 prominent masses as he and other workers describe, they w^ould 

 doubtless, after some of the great number of fixers and stains I 

 have employed, been easily detected. Degeneration products, 

 which I mention subsequently, are seen in the cells, but could 

 not be mistaken for a product of regular glandular activity. 



Crystals, as described by Reinke ('96) in the interstitial cells 

 of man, and by Duesberg ('18) in the opossum, have not been 

 encountered in Necturus. Neither do I find pigment, such as 

 Rasmussen ('17) describes in the woodchuck. The region occu- 



