SECONDARY SEXUAL CHARACTERS. 37 



cells might be explained. At the same time the enlarged inter- 

 stitial cells exerted a pressure on the tubule cells which made 

 them crowd closer together than usual. This interpretation is 

 not admissible, because the cells within the tubule began to 

 swell at a time when the connective tissue layer separating tubule 

 and interstitial tissue was not yet broken through. At first the 

 enlarging cells still possessed the nucleus characteristic of the 

 tubule cells and only gradually the character of the nucleus 

 changed concomitantly with the later stages of the transform- 

 ation. 



2. It might be assumed that an actual transformation of 

 tubule tissue into interstitial tissue took place, and that the gland- 

 like interstitial tissue was merely further differentiated tubular 

 gland tissue. Many pictures seemed to suggest such an inter- 

 pretation. However, the fact that in many other places, es- 

 pecially where the interstitial cells were still solid and smaller, 

 and, therefore, younger, the line of demarkation between tubule 

 and interstitial tissue throughout was very sharp made, after all, 

 this interpretation improbable. Furthermore, it would be con- 

 tradicted by what is known of the origin of the interstitial cells. 



3. It is most probable that the same factors which produce the 

 changes in the interstitial cells, at the same time called forth 

 similar changes in the tubule cells. Probably certain substances 

 furnished by the lymph or blood vessels were simultaneously 

 responsible for both sets of changes. In favor of this inter- 

 pretation might be cited the fact that we did not usually find in 

 the tubules that extreme vacuolization, which was present in 

 some of the interstitial cells. We are, therefore, inclined to adopt 

 the third interpretation. 



The round bodies which we found near the place where nor- 

 mally the ovaries are situated therefore represent undescended 

 testicles. There is a system of ducts leading from the testicle 

 tubules to the surrounding fat tissue. The tubules are relatively 

 simple structures in which spermatogenesis does not take place. 

 The epithelium lining them corresponds to the sustentacular cells 

 of the normal testis. There is present an extremely marked 

 development of the interstitial cells. The structure of this tes- 

 ticle differs, therefore, markedly from the normal testicle of the 



