480 ATONIC DISEASES. 



From this minute description it may be gathered, that the ova are 

 in enormous numbers, each section of the worm being capable of 

 producing them to an almost indefinite extent ; and as they are 

 passed out of the body with the foeces, it is not surprising that 

 they are readily communicated from one dog to another, as is 

 almost proved to be the case from the fact of their prevalence in 

 certain kennels and absence from others, The injury caused by 

 these worms is twofold, depending partly upon the abstraction 

 of nourishment, which is absorbed by the worm, and partly by 

 the irritation produced by its presence in the intestines ; and 

 hence it is of the utmost importance to get rid of so troublesome 

 a customer. 



The Kidney -worm (Strongyhcs gigas) "inhabits the kidney 

 of the dog, as well as that of the wolf, otter, raccoon, glutton, 

 horse, and bull (see fig. 6.) It is generally of a dark blood- 

 colour, which seems to be owing to the nature of its food, which 

 is derived from the vessels of the kidney, as, when suppuration 

 has taken place round it, the worm has been found of a whitish 

 hue." In the human kidney it has been known to attain the 

 length of three feet, with a diameter of half an inch. " The head 

 (a) is obtuse, the mouth orbicular and surrounded by six hemi- 

 spherical papillae (a) ; the body is slightly impressed with circular 

 striae, and with two longitudinal impressions ; the tail is incurved 

 in the male, and terminated by a dilated point or bursa (b), from 

 the base of which the single intromittent spiculum (6) projects. 

 In the female the caudal extremity is less attenuated and straighter, 

 with the anus (c) a little below the apex." (Cyclopcedia of 

 Anatomy, art. Entozoa.) I have been thus particular in inserting 

 descriptions of these worms, because I find that the study of their 

 natural history is becoming more general ; and as there is a large 

 field for the microscopic inquirer, it is well to have a good ground 



