854 Journal of Agricultural Research voi.xx, No. n 



measure, inasmuch as trichinae are not inoffensive as intestinal parasites 

 apart from the damage done by their migrating larvae. Rats, for example, 

 commonly die from intestinal trichinosis prior to the migration of the 

 larvae, and human beings also often suffer seriously from the effects of 

 the intestinal stage of the parasites during the first few days after infec- 

 tion before the migrating larvae have been produced. Consequently, 

 unless the X-ray treatment has the effect of diminishing the injurious 

 action of the intestinal stage of trichinae upon the host as well as of 

 destroying their powers of reproduction, it can scarcely be considered a 

 satisfactory prophylactic measure. It is of interest to note in this 

 connection that Tyzzer and Honeij ' found that encysted trichinae that 

 had been subjected to radium radiation failed to develop in mice. These 

 investigators also determined that whereas radium radiation failed to 

 destroy sexually mature trichinae in live rats, trichinae in rats which 

 were radiated beginning with the second day after ingestion of trichinous 

 meat showed retardation in development. Radiation of the larvae in 

 rats before they have begun to develop proved fatal to them. 



SUMMARY 



(1) Encysted trichinae are injured by relatively heavy dosages of 

 X-rays. So far as has been determined the injuries are not visible in 

 the encysted or artificially decapsuled larvae as structural or functional 

 disturbances but become apparent only when the larvae reach a suitable 

 host animal in whose intestine they are normally capable of continuing 

 their development. 



(2) Trichinae from meat that has been exposed to strong dosages of 

 X-rays undergo rapid granular degeneration in the intestines of suitable 

 hosts before they attain maturity. 



(3) Encysted larvae that have been exposed to lower but still injurious 

 dosages of X-rays are able to continue development in the intestines of 

 suitable hosts. Such larvae, however, do not attain structural and 

 functional sex maturity. The sex cells appear to be atrophied, and no 

 evidence of successful copulation can be found. X-rays, therefore, 

 appear to exert a more or less selective action on the gonads of trichinae. 



(4) Trichinae appear to exhibit considerable variation in their suscepti- 

 bility to X-rays, since certain dosages injured some parasites and failed 

 to injure others. Whether the apparent variation in susceptibility of 

 trichinae to X-rays is an expression of an actual physiological variation 

 or may be accounted for by other factors has not been determined. 



(5) The experiments described in this paper do not warrant any 

 definite conclusions as to the feasibility of using X-ray radiation as a 

 practical means of destroying trichinae in pork. 



1 Tyzzer, E. E., and Honeij, James A. the effects of radiation on the development of trichi- 



NELLA SPIRALIS WITH RESPECT TO ITS APPLICATION TO THE TREATMENT OF OTHER PARASITIC DISEASES. In 



Jour. Par., v. 3, no. 2, p. 43-56, 1 pi. 1916. 



