181 ANIMAL PARASITES. 



not of very large size, cannot generally be very dangerous, but 

 their general prognosis agrees with that of the non-animal hyda- 

 tids in the human body, and is to be judged according to the 

 organ of the abdomen attacked. The position of the Cysticerci 

 in the mesentery is undoubtedly more favorable than in the liver. 

 I should not, however, suppose that these parasites, if they oc- 

 curred in larger numbers, would be as indifferent and harmless in 

 man, as is often the case when we find them in our domestic ani- 

 mals ; because from the upright position of man, they much more 

 readily produce inconvenience from pressure in him than in the 

 lower animals, in which swellings of this kind are constantly being 

 drawn towards the anterior wall of the abdomen by their own 

 weight, and prevented from pressing upon the vital organs and 

 upon the large blood-vessels which lie more backward. For this 

 reason, I think, we must not push the analogy between cystic 

 worms occurring in man and animals too far; and we may expect 

 that injurious consequences, such as dropsy and other phenomena, 

 may occur much more readily in man than in animals, a circum- 

 stance which, as far as I know, has been hitherto but little taken 

 into consideration in comparative pathology. 



Therapeutics. — The indications are of two kinds — 1. Prophy- 

 laxis. 2. Direct therapeutics. Recent observations have con- 

 vinced me that even in animals it is not a matter of indifference 

 when a large number of them are present in one animal. 



1. The prophylaxis is easy in theory, as it can only con- 

 sist in the counsel not to infect ourselves with the eggs of 

 Teenia e Cysticerco teauicolli ; but difficult in practice, as we 

 cannot easily state the mode in which we can best protect our- 

 selves from this infection. That Cysticerci tenuicolles are pro- 

 duced by swallowing the eggs of the above-mentioned Tcenia, is 

 as fully proved by experiment as the production of Cysticercus 

 celluloses from the eggs of T. solium. I first administered the 

 eggs of this Tcenia to three old sheep, without their exhibiting 

 any Cysticerci. One of these sheep became vertiginous, but, as 

 appeared on dissection, not in consequence of the migration and 

 development of the embryos of Cestodea in the brain, but in con- 

 sequence of an Oestrus Ovis in the frontal sinus. I then fed two 

 lambs, and found in one of them an irritation of the brain and 

 spots of exudation in various places, but no trace of a cystic 

 worm, although the dissection was performed four weeks after the 



