432 ATONIC DISEASES. 



and h a group of three as actually discharged from the intestine of 

 a dog in which they were thus knotted. I have often seen from 

 six to a dozen round worms thus collected together, so as when 

 discharged to form a solid mass as large as an e^^. Like the last 

 species they are propagated by ova, but sometimes these are 

 hatched in the body of the parent, so that a large worm may be 

 seen full of small ones. This species occasions much more incon- 

 venience than the maw- worm, but still far less than the tape- 

 worm. 



Tape-worms in the dog are described by foreign writers as of 

 five kinds, of which the Twnia solium and Bothriocephalm latus are 

 common to man and the dog. The others are not readily distin- 

 guished from these two, and all are now said to be developed from 

 the hydatid forms found in the livers of sheep, rabbits, &c. The 

 peculiarity in the bothriocephalus consists in the shape of the head 

 (see fig. 4), which has two lateral longitudinal grooves (bofhria), 

 while that of the true taenia is hemispherical. The following is a 

 description according to Professor Owen : — " The Ihiiia soJimn 

 attains the length of several feet, extending sometimes from the 

 mouth to the anus. The breadth varies from one-fourth of a line 

 at its anterior part to three or four lines towards the posterior part 

 of the body, which then again diminishes. The head [fig. 3, a) is 

 small, and generally hemispherical, broader than long, and often 

 as if truncated anteriorly ; the four mouths, or oscula, are situated 

 on the anterior surface, and surround the central rostellum, which 

 is very short, terminated by a minute apical papilla, and surround- 

 ed by a double circle of small recurved hooks. The segments of 



