Account of a Filaria in a Horse’s Eye. 293 
There remains, therefore, but one other theory, and that is the 
one which attributes the origin of intestinal and visceral worms, 
in all cases, to ova. Ehrenberg has clearly proved by his care- 
ful microscopical observations, that these animals have organs of 
reproduction clearly developed, and never deficient ; indeed, sur- 
passing in development, for the most part, those of other organic 
systems; thus plainly pointing to a predominant cyclical develop- 
ment, in the same manner as we find in the higher organisms. 
Ehrenberg has also shown that the fecundity of these animals is 
most astonishing, each female producing thousands, if not millions 
of ovaatatime. The same diligent and accurate observer states, 
that if we carefully examine animal bodies, whether of man or 
other animals, we shall, in nearly all cases, discover worms of 
some kind, and that we do not meet with more, he thinks is ow- 
ing to the great difficulties in the way of the development of the 
ova, among which the resistance of the vital principle is not the 
least. He therefore believes that the eggs of intestinal worms 
are taken into the circulation and carried into all parts of the body, 
but are developed only where the particular conditions requisite 
for this purpose are favorable. ‘The “Smaller diameter of the 
finest vessels through which they have to pass,” he remarks, 
“does not appear to me to present any important difficulty, be- 
cause these, as we see in every inflammation, become easily and 
quickly expanded as soon as they are irritated; and these eggs 
may, as excretive bodies, like every body which i is foreign to our 
organism, act in an irritative manner, and may be taken up by 
the embouchures of the absorbents and be propelled along with 
increased activity through them ; that this is the case with mer- | 
cury, pus and other matters, has been already received as an ob- 
pa 5 fact. It is even probable that the eggs of the Hntozoa 
and their propulsion through the vaseular system may be an im- 
portant morbid matter hitherto overlooked, and which causes a 
part of the phenomena comprehended under the name scrofula. 
In bodies which are particularly favorable to the development 
of worms, there must necessarily be an innumerable quantity of 
secreted eggs of these parasites, which, if they are not expelled 
by the intestinal canal or by the prime vie, must, as foreign bod- 
ies, produce disorders. If the absorption takes place entirely or 
for the most part in the lymphatics, it would occasion their gen- 
eral or sole influence upon that system. Obstructions in the 
Vol, xxxrx, No. 2.—July-September, 1840, 38 
