234 MM. Gruby and 0. Delafond on the 



vessels, we had, nevertheless, been unable to account for their 

 origin. 



We continued our researches, and, after two years of labo- 

 rious and patient study, we discovered in the blood of a dog 

 with vermiferous blood, which died from the effects of a diet 

 composed exclusively of gelatine, some large worms visible 

 to the naked eye. These entozoa, six in number, of which 

 four were females and two males, were lying in a large blood 

 clot, of recent formation, which filled and dilated the right 

 ventricle of the heart. These helminths were white, filiform, 

 from 14 to 20 centimetres in length, and from one to one- 

 and-a-half centimetres in diameter. We have been able to 

 make out the zoological characters of the male and of the 

 female, to recognise the anatomical disposition of the organs, 

 external and internal, — to study the development of the 

 eggs in the ovaries, and of the embryo in the oviduct, and to 

 convince ourselves that these embryos were identical with the 

 microscopic filaria which we had seen circulating with the 

 blood in all the vessels of several dogs. 



The blood of the animal in which we found these large worms, 

 itself contained so great a number of microscopic filaria, that 

 we were able to count as many as twelve or fifteen of them 

 in one drop of blood. We observed that the large worms 

 belonged to the genus Filaria, and to the species papillosa, 

 but that these filaria possessed besides some distinctive 

 characters which must make them be considered as a species 

 still unknown. We propose to give to this Nematoidea the 

 name Filaria papillosa hmmatica canis domestici. Founding 

 on the facts we have just stated, we believe ourselves autho- 

 rised in concluding, that the large filaria of the blood of the 

 domestic dog lay the eggs of the microscopic filaria in that 

 liquid. These young filaria, up to a certain period of their 

 development, circulate with the blood in all the vessels. It 

 is not until after they have acquired a diameter greater than 

 that of the capillaries that they abide in the heart and the 

 large blood canals. 



The discovery of these adult filaria had brought us to an im- 

 portant point, but our researches were by no means finished. 

 'A crowd of interesting questions still remained for elucida- 

 tion. The following are the results of our researches : — 



