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 ova at a time. 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 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- 

 served fact. It is even probable that the eggs of the Entozoa 

 and their propulsion through the vascular 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^nm^ vim^ 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. xxxix, No. 2.— July-September, 1840. 38 



