144 



WALTER LAWRENCE. 



phenomenon described in a preceding paragraph. Although 

 there was motility in some of the sperm after nine days abdominal 

 retention the per cent, which were motile was considerably less 

 than in the case just cited. With the loss in motility the tendency 

 to clump is lost, so that in sperm from a ten-day abdominally 

 retained epididymis there is little or no clumping, although the 

 sperm bodies may appear approximately normal for a month 

 longer in the ductus epididymis and vas. 



It is a surprising fact in view of the extremely rapid degenera- 

 tion within the seminiferous tubule that spermatozoa morpho- 

 logically normal are found in the epididymis for such long periods 

 of time after all other elements have disappeared. Thus within 

 twenty days the seminiferous tubules are approximately empty 

 whereas the epididymis contains sperm apparently normal so 

 far as morphology is concerned for thirty-seven days. It is also 

 significant that the rapidity of degeneration of spermatozoa 

 varies in different parts of the passages. Thus in the efferent 

 ducts and in the proximal portion of the ductus epididymis 

 degeneration is marked at twenty to thirty days, in the thicker 

 walled distal portion of the ductus epididymis and vas sperm 

 are considerably less altered after retention of 113 days. To 

 account for this difference in rapidity of degeneration is beyond 

 the scope of this paper, but it might be suggested that probably 

 the cause is referable to the difference in vascularity of these parts. 



Since in the vas, degeneration is least marked, and since this 

 is the real reservoir for mature sperm, it would be reasonable to 

 suppose that vitality would be retained as long or even longer 

 than any place inside or outside the animal body, as here they 

 are surrounded by what would be supposed to be the most 

 suitable environment. As sperm are capable of showing motility 

 for nine days in this location after ligature, and as these sperm 

 were present an indeterminate length of time before operation, 

 we can state with assurance that the maximum life of the guinea 

 pig sperm in the male genital tract is more than nine clays. 



D. VASCULAR CHANGES IN RELATION TO THE 

 DEGENERATIVE PROCESS. 



Having noticed that testes made cryptorchid for from six to 

 sixteen clays were somewhat hyperemic as evidenced by the 



