Filar ia in the Blood of the Domestic Dog. 235 



1a/, The number of the microscopic filaria in the blood of 

 certain dogs may be estimated approximately from 11,000 

 to near 224,000. The mean number in twenty dogs was more 

 than 52,000. 



2d, The microscopic filaria, having a less diameter than 

 the globules of the blood, circulate in the smallest capillary 

 vessels through which the globules can pass. One drop of 

 blood taken from the vessels, it matters not in what part of 

 the body, nor in what season of the year, contains these little 

 Hematozoa. 



Zd, The chyle and the lymph of the dogs whose blood con- 

 tains microscopic filaria, even in very great number, do not 

 contain any of these worms. 



4/A, The normal liquid secretions, such as the saliva, the 

 bile, the pancreatic juice, the urine, the spermatic fluid, the 

 serosity of the great serous membranes, as well as the fluids 

 abnormally secreted, do not contain any of these minute 

 animals. 



5M, Twenty-eight dogs with vermiferous blood, of differ- 

 ent kinds and ages, kept, some during several months, others 

 during more than five years, animals which had approxi- 

 mately from 11,000 to near 224,000 microscopic filaria in their 

 blood, have been dissected in the course of the winter, the 

 spring, the summer, and the autumn, with the greatest care, 

 without a single filaria, invisible or visible to the naked eye, 

 having been perceived in the different tissues. We think, 

 then, we are able to affirm, that the filaria of the dog, whether 

 microscopic or of from 14 to 20 centimetres in length, and 

 near 1 millimetre in diameter, or of the size of a thick 

 thread, lives exclusively in the blood during all seasons of 

 the year, draws nourishment from that fluid, and never 

 abandons it. 



6M, The frequency and the rarity of dogs having vermi- 

 ferous blood, and of those without it, calculated from 480 

 dogs, the blood of which has been examined, is, in the mean 

 proportion, one dog with vermiferous blood to twenty or 

 twenty-five without it. 



7M, Vermiferous blood occurs more frequently in old and 

 adult dogs than in young. 



8///, These worms appear in the blood of dogs without 



