STUDIES ON CYTOLYSINS — SPERMATOTOXINS 221 



results of these tests indicate that the vitality of the spermatozoa 

 of the sperm-treated males has been impaired in vivo by the 

 spermatotoxic serum rather than as the result of a general con- 

 stitutional weakening due to the presence of a foreign protein in 

 the blood. 



From time to time, in testing the spermatotoxic sera of various 

 males, it was observed that while the great majority of spermato- 

 zoa were speedily immobilized in such sera, a few would flicker 

 feebty for hours longer. It was inferred that this was due to the 

 using up of the alexin (complement) of the spermatotoxic serum 

 in the immobihzing reaction. With this gone, there was no 

 reason why the spermatozoa should not live as long in such 

 serum as in normal serum. To put the matter to a test, sperma- 

 totoxic serum was drawn from male 32 Al, February 17th, and 

 divided into two parts. One of these was 'inactivated' (alexin 

 destroyed) by heating it to 56°C. for thirty minutes. A control 

 of normal serum was also used. Normal spermatozoa subjected 

 to the spermatotoxic serum of 32A1 were immobilized by the 

 end of three and one-half hours, but were still moving in the 

 inactivated spermatotoxic serum and in the normal serum twenty- 

 four hours later when observations were discontinued. The 

 spermatozoa of 32A1 were immobilized in his own serum at the 

 end of two and one-half hours, although in his inactivated 

 serum they continued to be very active at the end of this time 

 and still showed considerable motion at the end of seven hours. 



Various investigators have described degeneration of the 

 seminal epithelium in different mammals due to occlusion or 

 resection of the ductus deferens. Kuntz,^ for instance, finds that 

 ligature and resection of the right ductus deferens in dogs in- 

 duces degeneration of the seminal epithelium not only of the 

 right but in the left testis as well. In view of the fact, estab- 

 lished through the present investigation, that an animal will 

 develop a toxin in its blood serum poisonous to its spermatozoa 

 and germinal epithelium when its own spermatozoa are intro- 

 duced into its blood stream, the possibility suggests itself that 

 the degenerative changes in seminal epithelium which follow 



* Anat. Rec, vol. 17, no. 4, Dec. 20, 1919. 



