394 Scientific Intelligence^- Zoology/. 



portance for physiology, pathology, and natural history, to shew, not 

 only the existence of entozoary worms in the blood, but to prove be- 

 sides that they continually circulate in this fluid, in animals which, 

 in their structure, make some approach to man. Now, as science is 

 still destitute of an instance proving in an absolute manner the cir- 

 culation of worms in the blood of Mammifera, we are anxious to com- 

 municate to the Academy the discovery we have made of entozoa cir- 

 culating in the blood of a dog of vigorous constitution, and apparently 

 in a state of good health. 



These worms are from 0"™.003 to 0'"'".005 in diameter, and about 

 0"".25 in length. The body is transparent and colourless. The 

 anterior extremity is obtuse, and the posterior or caudal extremity 

 terminates in a very slender filament. In the anterior part a small 

 furrow is observable, about 0'"".005 in length, which may be regarded 

 as a buccal fissure. 



In all its characters, this species of hematozoaria belongs to the 

 genus Filaria. 



The motions of these animals are very active. Life continues for 

 no less than ten days after the blood has been extracted from the 

 vessels, and placed in a vase at a temperature of 15 degrees of the 

 centigrade scale. On examining a drop of blood under the glass of 

 a microscope, we perceive these hematozaoria swimming about with 

 an undulatory movement between the sanguineous globules, bending 

 and unbending, twisting, and untwisting themselves with great vi- 

 vacity. 



In order to determine whether these worms existed in every part 

 of the circulating stream, we examined the blood of the coccygian 

 arteries, of the external jugulars, the capillaries of the conjunctive, 

 the mucous vessels of the mouth, of the skin, and of the muscles, and 

 in everywhere the fluid presented us with these entozoa. 



For twenty days we daily opened the capillary vessels of different 

 parts of the skin, and the mucous vessels of the mouth, and always 

 ascertained the presence of these animals. 



The urine and excrementitial matter contained none of thenf. 



The diameter of the globules of the blood in a dog is from 0""".007 

 to 0'"'".008, that of the Filaria is from 0™'".003 to 0™".005. There 

 is not, therefore, the least doubt that this worm can circulate where- 

 ever the blood requires to pass. After many researches undertaken 

 for the purpose of ascertaining the quantity of blood existing in the 

 vessels of dogs of medium size, we estimate that the dog in question 

 had I'^ii-.SOO of blood in circulation. Now a drop of this blood weighs 

 0'^''-.067, and in this drop there are usually from four to five filaria. 



