TRICHINAE. 
57 
Such embryos and pregnant females become mixed with the 
manure and bedding of the hog pen and may be taken up by 
other swine, or even by the original autosite, thereby leading to a 
second invasion induced by itself. 
By the above, however, we have a course of invasion by which 
the swine themselves are the sole factors. 
Is there no other factor (or factors) in the question ? 
We have previously remarked that wild swine have been 
found infected with trichinae, also that cats, dogs, foxes, the mar¬ 
mot and other wild animals serve as autosites to them. 
*“ Dr. Clendenin, of Ostend, examined a pike caught in the 
North Sea, and found it infected with trichinae. He conjectured 
that the fish must have fed from trichin-infected refuse in the 
\ 
harbor of Ostend and by this means have become infected. 15 
But of all the animals by which these parasites have been 
found, none have that interest, aside from the swine, to the hy¬ 
gienist and experimental pathologist, which is enjoyed by the rat, 
on account of a hypothetical aetiological connection between the 
trichinae, which, it has been found, infect them in large numbers, 
and those of swine. 
Leisering is the originator of this hypothesis. The following 
figures sufficiently prove that the rat lodges trichinae in its mus¬ 
cles, even to a larger extent than any other animal which has as 
yet been subjected to examination. Of 704 rats from different 
parts of Germany, which have been subjected to examination, 59 
were found triehinous,—8.3 per cent. 
Per cent. 
Of 208 rats from German knackers, 46 found trich- 
inous. 22.1 
224 “ ‘ 
trichinious - 
272 “ < 
inous - 
326 “ 
“ slaughter houses, 12 found 
- 6.00 
“ other places, 1 found trich- 
.0.3 
“ “ 39 “ 11.0 
Of 51 rats caught at the knacker establishment at Spectacle 
Island, Boston Harbor, 30 were found by myself to be triehinous, 
the tongues having been used for examination. The proprietor 
*Archiv fur Thierheilkunde Berlin, vol. 5, p. 147. 
