290 DR. T. S. COBBOLD ON ENTOZOA T^^ THE DOG. 



not generally known, even by those who have some acquaintance 

 with helminthological matters, that the larvse of this tapeworm 

 sometimes infest the rabbit, giving rise to a formidable disease 

 having its seat in the muscles and soft parts of that animal. In 

 a paper communicated to this Society, I have already explained 

 that Mr. C. B. Eose, F.G-.S., was the first to direct attention to 

 this important fact ; but his explicit statements on this head have 

 been either carelessly overlooked, or purposely disregarded. I 

 regret to observe that there are persons who, whilst fairly record- 

 ing the information they obtain from foreign writers, appear to be 

 studiously careful to avoid giving credit to the labours of their 

 own countrymen. In the curious discovery before us we have 

 another unexpected source indicated whence the dog may obtain 

 the adult parasite, and thus, in its turn, afflict another group of 

 creatures with the so-called bladder-worm disease. 



14. Tcenia cucumerina. — Without doubt this is the commonest 

 of all the forms of canine entozoa. I have little hesitation in say- 

 ing tbat it is present in two out of every three dogs at present 

 living in this country, excluding puppies up to three months old. 

 KJrabbe found it present in 48 per cent, at Copenhagen, and in 

 57 per cent, in Iceland. It appears to be very prevalent through- 

 out Europe, and probably is more or less so in all other countries. 

 So far as we know, the cucumerine tapeworm is a tolerably harm- 

 less parasite ; but, notwithstanding the efibrts of investigators, 

 nothing certain is understood respecting its true larval source. In 

 the adult state it sometimes occurs in prodigious numbers, and 

 often associated with other parasites. In one valuable animal, a 

 pointer, which died suddenly, I found between 500 and 600 of these 

 parasites, associated with numerous examples of three other kinds 

 of entozoa. Clearly, in this particular instance, entozoa were the 

 cause of the dog's death. If the canine tapeworm species, which 

 are dangerous to human life, became as abundant in this country 

 as the harmless Tcenia cucumerina is thus shown to be, our 

 mortality would be increased by many thousands annually. This 

 will be made more apparent in the sequel. 



15. Tcenia serrata. — Though by no means so abundant as the 

 preceding, this form is nevertheless siifficiently common, whilst 

 it is also more injurious to the bearer. Taking one variety of dog 

 with another, I should say that it occurs in at least five per cent, 

 of our English dogs ; but in harriers and greyhounds I have little 

 doubt that its presence is all but invariable. At Copenhagen 

 Dr. Krabbe only encountered this parasite once ; and in Iceland it 



