436 



ATONIC DISEASES. 



Tic-, n. 



colour, whicli seems to be owing to the 

 nature of its food, wliich is derived 

 from the vessels of tlie kidney, as, 

 when sujDpuration 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 dia- 

 meter of half an inch. " The head 

 (a) is obtuse, the mouth orbicular and 

 surrounded by six hemispherical papillae 

 (a) ; the body is slightly impressed with 

 circular striae, and with two longitu- 

 dinal 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 (b) projects. In the female 

 the caudal extremity is less attenuated 

 and straighter, with the anus (c) a 

 little below the apex." {Cyclopedia of 

 Anatomy, art. Entozoa.) 1 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 



