666 
Trichina and their Distribution, [November, 
swine the infection has become greatly increased since the 
abominable pra<5tice of feeding them upon butchers’ offal 
became general ; and it is remarked that the very parts 
given to pigs — such as the diaphragm, and the junctions of 
muscles and tendons — are exceedingly liable to contain 
Trichina. But we must beware of supposing that swine fed 
upon corn, fruits, mast, &c., must necessarily escape the 
pest. A wild boar killed in November last, near Khiam, in 
Syria, according to the “ Lancet,” communicated trichinosis 
to two hundred and sixty-two persons, several of whom 
died. It appears that the wild boar, when grubbing in the 
earth for roots, frequently snaps up and devours rats, field- 
mice, &c. The habits of tame and half-wild swine, when 
turned out into the forests, are precisely similar. Even 
when in the sty, pigs have been known to capture and 
devour the rats which came to steal their food. It often 
happens, also, that rats which have been worried by dogs — ■ 
who rarely, if ever, eat them — are left in the way of pigs, 
and get eaten. Dogs are much given to prey upon slaughter- 
house offal, yet are seldom found trichinised. Mr. Phin has 
never met with an authenticated instance. Cats, on the 
other hand, according to Dr. Seiler, of Philadelphia, are 
very frequently infedted. Mr. Phin considers that the cause 
of this lies in the fadt that cats eat rats, while dogs never 
eat them. We can scarcely accept this contention. We 
have known cats who were adepts at ratting, but who never 
devoured their prey. Others, if very hungry, will eat the 
liver, and sometimes the back of the neck, which it must 
be admitted is a very likely habitat for Trichina. Cats, 
however, according to Dr. T. Spencer Cobbold, F.R.S., are 
exceedingly subjedt to parasites.* Rats which prey upon 
slaughter-house offal are often trichinised. Pikes may 
conceivably become trichinised by devouring rats in the 
rivers. 
The question may here be raised, What animal is the 
original nidus of the Trichina ? At present we see the pig 
receiving them from the rat, and the rat again becoming 
infedted by devouring pork. But we are unable to lay our 
finger on the beginning of the series. 
A second source of infedtion must be sought in the excre- 
ments of animals which have recently become infested with 
Trichina. Mr. Phin observes that the pig, the rat, and the 
dog “ are all ravenously fond of excrementitious matter, 
eating it greedily when they can get at it.” So, we may 
* Internal Parasites of our Domesticated Animals, p. 124. 
