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MISCELLANEOUS. 

 Investigation of Trichina spiralis. By R. LEUCKART. 



PROFESSOR LEUCKART has communicated the following results of 

 his investigation of Trichina spiralis to the Royal Academy of Sciences 

 of Gottingen : 



1. Trichina spiralis is the young state of a hitherto unknown 

 small Nematode worm (of l'5-2'8 mill, in length), for which the 

 generic name Trichina must be retained. 



2. It inhabits the intestinal canal of numerous warm-blooded ani- 

 mals, not only Mammalia (dogs, cats, pigs, sheep, rabbits, and mice, 

 also, undoubtedly, man), but also Birds (the common fowl), and 

 indeed always in large quantity. 



3. The intestinal Trichina attains its full sexual maturity as early 

 as two days after its immigration. 



4. The eggs of the female are developed in the vagina into minute 

 Filaria-\ik& embryos, which are extruded without egg-shells (from 

 the sixth day onwards). 



5. The new-born young immediately set about their migration. 

 They penetrate the wall of the intestine, and pass through the cavity 

 of the abdomen directly into the muscular envelope of their host. 



6. The course upon which they advance is indicated beforehand 

 by the intermuscular masses of cellular tissue. 



7. The majority of the migrating embryos remain in the groups of 

 muscles immediately inclosing the cavity of the body (the abdominal 

 and thoracic cavities), especially the smaller ones and those con- 

 taining most cellular tissue. 



8. The embryos penetrate into the interior of the individual mus- 

 cular fasciculi, and here attain, within fourteen days, the size and 

 organization of the well-known Trichina spiralis. 



9. The infected muscular fasciculus loses its previous structure 

 immediately after the penetration, the fibrillae becoming broken up 

 into a finely granular substance, and the muscular corpuscles acquir- 

 ing the form of oval nucleated cells. 



10. Up to the full development of the Trichina spiralis, the infected 

 muscular fasciculus still retains its original tubular form ; whilst sub- 

 sequently its sarcolemma thickens and it becomes gradually shrivelled 

 from the extremities. 



1 1 . The spot occupied by the parasite persists, in the form of a 

 spindle-shaped enlargement, in which the well-known lemon-shaped 

 or globular calcareous shell is afterwards deposited (although only 

 after a long time). 



12. The migration and development of the embryos take place 

 also after the transference of pregnant Trichince into the intestine of 

 another (suitable) host. 



13. The further development of the Trichina spiralis into the 

 sexually mature animal is quite independent of the formation of this 

 calcareous shell, and takes place as soon as the young state is fully 

 developed. 



