154 PARASITES OF MAX 



The organised capsules are not essential to the further develop- 

 ment of the parasite, and are rather to be regarded as abnormal 

 formations, or rather, perhaps, as products resulting from an 

 effort of nature to protect and thus prolong the life of the 

 occupant. They are frequently altogether wanting. The cap- 

 suled Trichinae measure ^" in length by about ^" in breadth. 

 When fully formed they not only exhibit a well-marked digestive 

 apparatus, but also reproductive organs, which are often, indeed, 

 sufficiently developed to determine the sex. 



Notwithstanding the large number of experiments that have 

 been more or less recently made by investigators, little or 

 nothing has been discovered calculated to disturb the conclu- 

 sions set forth by Leuckart, who writes as follows : " (1) Tri- 

 china spiralis is the juvenile state of a little round worm, pre- 

 viously unknown, to which the generic title of Trichina must 

 remain attached. (2) The sexually mature Trichina inhabits 

 the intestinal canal of numerous warm-blooded animals, espe- 

 cially mammalia (also of man), and constantly in great num- 

 bers. The duration of its life extends from four to five 

 weeks. (3) At the second day after their introduction the 

 intestinal Trichinae attain their full sexual maturity. (4) The 

 eggs of the female Trichinae are developed within the uterus of 

 the mother, into minute filaria-like embryos, which, from the 

 sixth day, are born without their egg-shells. The number of 

 young in each mother-worm is at least from ten to fifteen 

 thousand. (5) The new-born young soon after commence 

 their wandering. They penetrate the walls of the intestine and 

 pass directly through the abdominal cavity into the muscles of 

 their bearers, where, if the conditions are otherwise favorable, 

 they are developed into the form hitherto known. (6) The 

 directions in which they proceed are in the course of the inter- 

 muscular connective tissues. (7) Only the striped muscle 

 (that of the heart excepted) contains Trichinae. The majority 

 of the wandering embryos remain in those sheathed muscular 

 groups which are nearest to the cavity of the body, especially 

 in those which are smaller and most supplied with connective 

 tissue. Speaking generally, their number decreases with the 

 distance from the abdomen, being, however, more numerous in 

 the anterior half of the body. (8) The embryos penetrate 

 into the interior of the separate muscular bundles, and here 

 already, after fourteen days, acquire the size and organisation 

 of the well-known Trichina spiralis. (9) Soon after the in- 



