GENERAL PATHOLOGY 
168 
those last diseases being spread all over. Man carries them on himself, or in 
his intestinal canal, without great damage, but also ready to become dangerous 
when, by special conditions of successive growths at the surface of wounds, 
in debilitated organisms or otherwise, their virulency is progressively rein¬ 
forced. 
And now virulency appears before us in a new light, which is not without 
alarm for humanity, unless Nature, in its evolutions through past centuries, has 
met ahead all the occasions of production of virulent or contagious diseases; which 
is most improbable. 
What is, for man or any other animal, an inoffensive microscopic organism ? 
It is a being which cannot develop itself in our body, or in that of that animal; 
but nothing proves that, if this microscopial being could penetrate into another of 
the thousand species of the creation, it could not invade it and make it sick. Its 
virulency, then strengthened by successive journeys into the members of that 
specie, might become in condition to invade other animals of large size—man or 
some domestic animal. By this method one may create new virulencies and new 
contagions. I am much inclined to believe that it is thus that through ages 
variola, syphilis, plague, yellow fever, &c., have appeared ; and that it is also by 
similar phenomena that at times appear some great epidemics—such as, for in¬ 
stance, the typhus I have mentioned. 
The facts observed at the time of variolation (inoculation of variola) had 
introduced in science the opposite opinion—that of the possible diminution of 
virulency by the journey of a virus through some subject. Jenner had this 
opinion, which has nothing improbable. However, till now we have not met 
with any examples of it, though we have carefully looked for them. 
These deductions, I hope, will find new proofs in subsequent communi¬ 
cations. 
^UPON SMALL ENCYSTED HELMINTHS WHICH MAY EASILY BE MIS¬ 
TAKEN FOR TRICHINA SPIRALIS. 
By M. Megnln. 
At the Society of Biology the author presented a paper on 
this subject, saying that “ since the discovery of trichina spiralis 
by Owen, numerous small worms have been assimilated, of simi¬ 
lar dimensions, encysted also, either under the peritoneum, in 
the muscles or the parenchymatous organs, or in the subcutaneous 
cellular tissue. It is thus that Siebold lias described, under the 
name of trichina, a worm found in small cysts of the peritoneum 
of some mamrnifera and birds as well as in the gray lizzard. Dujar- 
din has also mentioned, under the name of trichina mflexa , a 
nematode forming a white, compact mass in the abdomen of a 
young fish of the Mediterranean Sea, of the gender Mullys. Tt 
