184 J- DUESBERG. 



as processes of the intercellular substance. No structure, at 

 least no visible structure, appears to be the substratum of these 

 processes. They represent, in my opinion, something like the 

 "sekretorischer Zerfall" supposed by Kumita, or the accumula- 

 tion along certain lines, perhaps in connection with protoplasmic 

 currents, of the product of secretion. Nor do the intercellular 

 spaces represent capillaries. Their irregular shape and the fact 

 that no endothelium seems to line them, show that they are, as 

 I have called them so far, merely intercellular spaces which 

 become more or less dilated according to the quantity of secretion 

 which is accumulated in them. Finally, that the space into 

 which this substance is poured is a capillary cannot be doubted, 

 for it is lined with a well-recognizable endothelium. Whether, 

 on the other hand, this capillary is a lymphatic or a bloodvessel 

 is not so easy to tell, and must be decided by methods other than 

 those employed by me. Nor do the bibliographic data give 

 any definite clue. Regaud (1897), who has made a special 

 study of the distribution of the lymphatics in the mammalian 

 testicle, finds that it is exceedingly variable in the different 

 species. He distinguishes three types: One in which the lym- 

 phatic net is exclusively peritesticular; another in which the 

 lymphatics penetrate as far as the corpus Highmori and the 

 interlobular septa; and a third, in which the lymphatics form a 

 network around the seminiferous tubules. It may be worth 

 while to determine sometime, in connection with the problem of 

 the excretion from the interstitial cells, to which type the opossum 

 belongs. 



To sum up, the product of secretion is accumulated in the 

 interstitial cell, then discharged into the intercellular spaces, 

 and from there passes into the circulation. Although this is one 

 of the clearest instances in which the secretion product of a gland 

 with internal secretion actually could be followed from the 

 glandular cell into the vascular system, owing probably to the 

 favorable staining properties of the secretion product, there are 

 similar observations in the literature. Reinke has already called 

 attention to the common staining properties of his crystals 

 and the testicular lymph, and concludes in favor of the passage 

 of the substance of these crystals into the lymphatics. Lenhossek 



