VIRCHOW, ON TRICHINA SPIRALIS. 45 



former; it also died at the end of a montli. The flesh 

 of this rabbit was used to infect three others at the same 

 time, two of which died three weeks afterwards, and the third 

 at the end of a month. I then fed two others, the one with 

 a good deal and the other with a small quantity of the flesh 

 of these three. The first died at the end of eight days, and 

 in this case nothing was revealed on the autopsy beyond an 

 intestinal catarrh ; the second died six weeks after the com- 

 mencement of the experiment. 



In all these animals, with the exception of the last but one, 

 all the red muscles, save the heart, contained such a quantity 

 of Trichina, that every portion examined under the micro- 

 scope exhibited several, sometimes as many as a dozen. 



We have here, then, to do with a mortal affection. 

 Attentive observation of the phenomena presented in these 

 animals, as well as in others, afforded the following results. 

 A few houi"s after the ingestion of the diseased flesh the 

 TrickhuB, disengaged from the muscle, are found free in the 

 stomach ; they pass thence into the duodenum, and afterwards 

 advance still further into the small intestine, where they 

 become developed. From the third or fourth day, ova or 

 spermatic cells are found, the sexes in the meanwhile 

 becoming distinctly marked. Shortly afterwards the ova are 

 impregnated, and young, living entozoa are developed within 

 the^ bodies of the female Trichince. The young are expelled 

 through the vaginal orifice, Aviiich is situated towards the 

 anterior half of the worm, and I have noticed them, under the 

 form of minute Filarias, in the mesenteric glands, and more 

 especially, in considerable number, in the serous cavities, 

 particularly the peritoneum and pericardium. According to 

 all appearance, they had traversed the walls of the intestine, 

 following, probably, the same course as that pursued by the 

 Psorospermia, according to the researches of one of my pupils. 

 Dr. Klebs ; that is to say, they penetrate into the epithelial 

 cells of the intestine. Further than this I have been unable 

 to discover them either in the blood or circulatory system. 



Continuing their migrations, they penetrate as far as the 

 inteiior of the primitive muscular fasciculi, where they may 

 ]>e found, as early even as three weeks after the alimentation, 

 in considerable numbers, and so far developed that the young 

 entozoa have almost attained a size equal to that of the 

 Trichinae contained in the flesh which had been administered. 



In order to be certain that before the experiment the 

 animal had no Trichina in its muscles, I have, on several 

 occasions, before administering the trichinized flesh, examined 

 a portion of muscular tissue excised from the back, in which 



