Mar. i, 1921 Effects of X-Rays on Trichince 853 



Experiment 25. — Rat 1 was killed on April 9; intestines contained 

 live trichina; sex cells of trichinae atrophied; diaphragm negative. Rat 

 2 was killed on April 16; diaphragm negative. Rat 3 died on April 19; 

 diaphragm negative. Rats 4 and 5 were killed on April 24; diaphragm 

 negative. 



Results of experiments oe series V. — The results of these exper- 

 iments are in harmony with the results of the experiments recorded in 

 the preceding pages. Trichinae that showed sex-cell injuries (experiments 

 23 and 25) failed to produce a new generation. That a few larvae in 

 experiment 23 escaped injury is evident from the results of the feeding 

 experiment with rat 4. It is interesting to note, however, that despite the 

 fact that the parasites showed evidence of injury they were still alive on 

 the fourteenth day after artificial infection. This indicates that X-rays 

 exert a selective action on the sex cells of trichinae and that injuries to the 

 sex cells do not necessarily affect the other vital functions of the parasites. 



DISCUSSION 



The results of the experiments described in the foregoing pages show 

 that trichinae may be seriously injured by X-ray radiation. It is inter- 

 esting to note that in experiments 1 to 6 inclusive (series I), larvae isolated 

 from the treated meat by artificial digestion appeared to be unaffected. 

 These larvae were normal as to color and general appearance, as viewed 

 through the microscope and as indicated by their reactions to heat 

 stimulation. The examination was made three days after treatment. 

 The larvae from the meat treated in experiments 1 and 2 (series I) were 

 incapable, however, of attaining full sexual maturity in the intestines of 

 rats or mice. Those in experiment 1 and some of those in experiment 

 2 underwent granular degeneration, while others in the latter experiment 

 succeeded in attaining maturity without being capable of functioning 

 sexually. The fact that no spermatozoa were found in the receptaculum 

 seminis of the female indicates that successful copulation had not taken 

 place. 



It is also of interest to observe that a considerable degree of variation 

 in resistance to X-rays is exhibited by trichinae, since certain dosages 

 proved to be destructive in some cases and not in others. This is pos- 

 sibly due, however, to other factors. It may be noted in this connec- 

 tion that trichinae exhibit considerable variation in their resistance to 

 cold * and in their resistance to heat. 2 



Assuming that a reliable and practically possible method of destroying 

 the vitality of the sex cells in trichinae by means of X-ray treatment of 

 infested meat can be perfected, which is quite uncertain, it is still ques- 

 tionable whether such a method would be acceptable as a prophylactic 



1 Ransom, B. H. effects of refrigeration upon the larvae of trichinella spiralis. In Jour. 

 Agr. Research, v. 5, no. 18, p. 819-854. 1916. Literature cited, p. 853-854. 



2 and Schwartz, Benjamin, effects of heat on trichin.e. In Jour. Agr. Research, v. 17, 



no. 5, p. 201-221. 1919. Literature cited, p. 220-221. 



