THE AMERICAN 



MONTHLY 



MICr. SCOPICAL JOURNAL 



Vol. it. 



New York, Makch, 1881. 



No. 3. 



Trichinae in relation to Public 

 Health. 



[The following article is an abstract 

 of a report to the Massachusetts 

 " State Board of Health, Lunacy and 

 Charity " (1879), by Dr. F. S. Billings, 

 M. v., which embraces the results of 

 original investigations by the author. 

 For the illustrations we are indebted 

 to the courtesy of the gentlemen 

 composing the Board. — Ed.] 



The literature treating of trichinosis 

 or trichiniasis is of comparatively 

 modern origin ; but we have no rea- 

 son to doubt that the disease pre- 

 vailed in swine at a very early date, 

 and the consequential disease in man 

 must have existed for years, if not 

 for centuries, before it was recog- 

 nized, perhaps dating back as far as 

 the use of pork as food. 



" Trichina spiralis is an extremely 

 minute nematoid helminth, the male in its 

 fully developed and sexually matured con- 

 dition measuring only one-eighteenth of 

 an inch, while the perfectly developed 

 female reaches a length of about one- 

 eighth of an inch ; body rounded and 

 filiform, usually slightly bent on itself, 

 rather thicker behind than in front, espec- 

 ially in the males ; head narrow, finely 

 pointed, unarmed, with a simple, central, 

 minute oval aperture ; posterior extremity 

 of the male furnished with a bilobed cau- 

 dal appendage, . . , female stouter than 

 the male, bluntly rounded posteriorly; 

 . . . eggs measuring ^^ of an inch from 

 pole to pole ; mode of reproduction vivi- 

 parous." * 



These parasitic pests assume two 

 forms, /. e., they may be met with 

 as intestinal trichinae and as muscle 

 trichinae, the first representing the 



* Cobbold, Entozoa, p. 335. 



sexually matured, the latter the em- 

 bryonal (usually capsulated), stage of 

 their existence. In order to offer 

 even a very condensed sketch of the 

 evolution which these parasites un- 

 dergo, it is better to begin with the 

 non-matured, or muscle form. The 

 parasite, in this stage of development. 



Fig. 9. — Fresh Triclfinous invasion. (Heller.) 



limits its abode entirely to the striated 

 or motory muscles. They have not 

 been found in the non-striated or 

 involuntary muscles, nor in the purely 

 adipose tissue. The capsulated para- 

 sites may be met with in the striated 

 muscles of all parts of the body ; the 

 heart seems, however, to be exempt. 



