On (he Filaria in the Blood of the Dog. 233 



On the Filaria in the Blood of the Domestic Dog. 

 By MM. Gruby and 0. Delafond * 



Messrs Schmitz, Baer, Valentin, Vogt, and Remak, had 

 previously noted the existence of species of Filaria, Mon- 

 ostoma, and Distoma, and of Infusoria, inhabiting the blood 

 of frogs, of certain fishes, and of some molluscs, but no ob- 

 server had proved the presence of Nematoidese living in the 

 blood of animals higher in the zoological scale. 



We first announced to the Academy, in the course of the 

 year 1843, that we had discovered Entozoa of the genus Filaria 

 living in the blood of certain domestic dogs, and circulating 

 with the globules of that fluid in all the vessels. Since 

 our communication to the Academy, MM. Erdl and Mayer 

 in 1843; Hyrtl Gros, and Ecker, in 1845; Chaussat and 

 Wedl, in 1848 ; and M. Guerin Meneville, in 1850 ; have 

 ascertained the presence of Hematozoa in the blood of the 

 field mouse, of the black rat, of several birds and fishes, of 

 the lobster, of the mussel, and of the earth and silk worms. 

 This third memoir, which we have the honour to present to 

 the Academy, comprises the researches to which, for many 

 years, we have devoted ourselves, on the w^orms living in the 

 blood of certain domestic dogs. 



We said, in our preceding communications, that this 

 Helminth was a Filaria ; and we called your attention to the 

 circumstance that, up to that time, we had not met with this 

 worm save in the microscopic state. Yet in studying this 

 helminth at different ages of the life of the dog, we had proved 

 that in the space of near two years, the microscopic filaria 

 were slowly developed in the blood, and that then the mouth, 

 the digestive canal, and the sexual organs appeared more 

 distinct. And, moreover, that, in three dogs with vermi- 

 ferous blood, aged from three to ten years, which we had 

 kept several years, whose blood we had examined after death, 

 and dissected the vessels and all the organs, we had never 

 found other than microscopic filaria. 



Although convinced of the constant existence of these 

 worms along with the globules of the blood in all the i^ed 



* Vide Coinptes Rendus, January 1852. 



