216 M. F. GUYER 



connective tissue. Traces of epididymis could be identified, 

 but all germ cells had disappeared. 



It is obvious from experiments 1 and 2 that fowls injected 

 repeatedly with the spermatozoa of rabbits will produce a sperma- 

 totoxic serum that is violently toxic in vitro and also toxic to 

 some degree in vivo. Of the three male rabbits (4A7, 25 and 83) 

 which survived the treatment, 4A7, judging from the breeding 

 test, had become completely sterile. However, his semen was 

 entirely free from living spermatozoa for only a few weeks. No 

 degenerative changes could be detected in his testes when sec- 

 tioned and examined microscopically. Male 25 did not become 

 sterile, at least for a prolonged period, according to the breeding 

 test, although as a result of the treatment his semen showed a 

 marked decrease in the number of inactive spermatozoa among 

 those which were present. Male 83, however, not only became 

 sterile, but exhibited a marked atrophy of the left testicle and 

 pronounced degenerative changes in the seminiferous tubules 

 of the right testicle. Spermatotoxins generated against the 

 spermatozoa of the rabbit were also toxic in vitro for the sperma- 

 tozoa of the guinea-pig. 



ISOSPERMATOTOXINS AND AUTOSPERMATOTOXINS IN RABBITS 



Experiment 3 



The purpose of the remaining experiments was to determine if 

 an animal can be made to produce antibodies against its own 

 tissues. Spermatozoa of rabbits were used as the elements to 

 be so tested. 



Two male (32A4 and an untagged one) and two female rabbits 

 (32A2 and 6A3) were employed in experiment 3. For each 

 treatment the semen of several males was drawn off from females 

 in the manner already described and mixed with sufficient normal 

 saline solution to provide a dose of about 3 cc. for each rabbit 

 injected. Injections were made into the marginal vein of the 

 ear. The dosage was as follows: October 18th, semen from 

 three males; October 25th, the same. Male 32A4 died im- 

 mediately after the second injection, but whether from thrombus 



