282 DB. T. S. COBBOLD ON ENTOZOA IN THE DOG. 



obvious in cases of ordinary accident, and also in those diseases 

 (hydrophobia for example), whose nature is either doubtful, or 

 which, at the least, cannot be said to have a parasitic origin ; but 

 it comes out much more forcibly when we confine our attention 

 exclusively to evils arising from entozoa harboured by our domes- 

 ticated animals in their capacity as " intermediary bearers." In 

 this communication I select the Dog as pointedly illustrating the 

 correctness of the proposition just advanced ; but, at the same 

 time, I may add that, excepting perhaps the equine quadrupeds, 

 I know of no important domestic animal which is not liable, by 

 the agency of its parasites, to inflict on the human body one or 

 other of the injuries just referred to — namely discomfort, disease, 

 or death. 



I may be permitted also to remark at the outset that all our 

 researches, and especially those of the experimental kind, tend to 

 show how the evils just mentioned may be averted ; and many of 

 our investigations having, in the first instance, a purely scientific 

 object have materially strengthened the results obtained by other 

 researches having merely a practical aim. It may be said that 

 the two methods should go hand in hand, or, at least, pari passu, 

 in order to ensure brilliant results. Already helminthologists 

 have obtained a considerable success ; but it is just one of those 

 successes in which the principal promoters are left without reward. 

 Self-imposed tasks of this kind are more or less the prerogative of 

 all the votaries of science, who, at least, have the satisfaction of 

 knowing that they contribute to the public good. 



To simplify and limit the subject matter before us, I offer, at 

 once, a complete and revised list of all the entozoa (species, 

 varieties, and larvae) at present known to infest the dog. In 

 many respects it is interesting to contrast this, as a whole, with 

 the rather more extended list of human entozoa which I have pre- 

 viously communicated to the Zoological Society ; but, as will here- 

 after be seen, the mutual relations subsisting between certain 

 members of the two series can only be established by a some- 

 what detailed notice respecting the individual forms. These are 

 as follows : — 



1. Solostoma alatum, Nitzsch. 



2. Spiroptera sanguinolenta, Eudolphi. 



3. DocTimius trigonocephalus, Dujardin. 



4. Trichosoma plica, Eudolphi. 



5. Tricliocephalus depressitisculus, Rudolphi. 



6. Trichina spiralis, Owen. 



