OUR DOMESTICATED ANIMALS. 99 



of cause and effect into the mind of the ordinary farmer 

 is no easy matter ; nevertheless, if such a truth could be 

 generally realised and accepted, there would soon be an 

 end not only to ' c gid," or turnside, but also to a whole 

 host of parasitic diseases, the nature of which, in conse- 

 quence of our helminthological researches, ought now to 

 be thoroughly well understood by intelligent agri- 

 culturists. 



In this connection it should be sufficient to state one 

 great result of all our experimental endeavours, leaving 

 the precise mode of dealing with the question, practically, 

 to the persons chiefly interested. In this view, there- 

 fore, I do not hesitate to put forth the following general 

 statement or proposition : " The propagation of entozoa 

 in general, and of tapeworms in particular, is intimately 

 connected with, and absolutely dependent upon, the pro- 

 miscuous association of different kinds of animals ; and, 

 as regards the production of parasitism amongst domes- 

 ticated animals used as food, it is perfectly certain that 

 the tapeworms of the dog play a most conspicuous part." 



As I have elsewhere remarked, it is not sufficient that 

 the sheep owner and grazier should look after the welfare 

 of his flocks and herds in the ordinary and direct manner 

 adverted to ; but he must see that no dog, either belong- 

 ing to himself or his neighbours, is permitted to go about 

 the land distributing the eggs of tapeworms with every 

 act of defsecation, as well as by dropping the ova off its 

 coat. 



If a dog harbouring tapeworms be allowed to plunge 

 into an ordinary field pond to wash himself, such an act 

 conveys numerous eggs into the water ; and the next 

 herbivorous animal that comes to slake its thirst will be 

 liable to drink in one or more of the parasite's eggz. If 



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