DK. T. S. COBBQLD ON ENTOZOA IN THE DOG. 289 



rather less abundant, being found, according to Krabbe, in 

 14 per cent, whereas in Iceland it is remarkably prevalent, 

 occurring in no less than 75 out of the 100 dogs which he 

 examined. This parasite is seldom found alone, and, being the 

 largest species liable to infest the dog, proves a formidable guest 

 to its canine host Up to the present time it has not been de- 

 scribed as occurring in man ; nevertheless I have seen portions 

 of a tapeworm, apparently referable to this species, which I was 

 assured had come from the human subject. From the first, I ex- 

 pressed the strongest doubts as to its source. The dog acquires this 

 parasite by swallowing the large cestode larvae which are frequently 

 attached to the viscera of the sheep. Dr. MoUer, as is well-known, 

 tried to rear this parasite in himself, by swallowing the fresh un- 

 cooked larvae {Cysticercus tenuicollis) , but he did not succeed; 

 and consequently we are not at present warranted in concluding 

 that this species can under any circumstances develope itself in 

 man. Mr. Simonds and myself have succeeded in rearing several 

 examples of this entozoon in the dog by direct experiment. One 

 or two instances are on record of the occurrence of the larvae of 

 this species in man; and I have myself pointed" to affirmative 

 evidence in yet another case. In none of these examples is there 

 any reason to suppose that the larvae in question did any harm ; 

 yet it would be very unadvisable to allow of steps being taken 

 which could promote its more frequent development within the 

 human host. Sewage-distribution where dogs abound would aid 

 in securing this undesirable end. 



13. TcBuia coenurtis. — This species is likewise obtained from the, 

 sheep, though by no means exclusively so, as some imperfectly 

 informed persons seem to suppose. Its prevalence in the dog, 

 however, is comparatively rare. I have succeeded in rearing it 

 without any difficulty, but I do not remember to have encountered 

 the entozoon in any dog which had not previously been made the 

 subject of a Coenurus-worm-f ceding. I need hardly say that its 

 larvalform {Coenurus cerebralis) gives rise to the "gid" in flocks ; 

 but it also proves detrimental to several other animals. Indirectly, 

 therefore, it affects man himself ; yet, in this country, the " gid- 

 disease" is seldom sufficiently prevalent to cause serious loss to 

 the sheep-breeder. In other countries, Hungary for example, 

 losses on this score are said to be very considerable. In Denmark 

 Dr. Krabbe encountered this entozoon in only 1 per cent, of the 

 dogs he dissected, but in Iceland he found it in no less than 18 per 

 cent. Clearly the "gid" must abound in that country. It is 



