78 



DISEASES OF THE DIGESTIVE APPARATUS. 



Fig. 25. 



Tsenia cuoumerina 

 (natural size). 



from 1.5 to 3 m. in length. In rare instances it has been found 

 to be 5 m., and the width of the developed segments is about 

 0.5 cm. Its head is nearly square, with four small, sucking 

 disks and a double crown of thirty-six hooks. The segments are 

 nearly square. In the middle of the colony they may even be 

 broader than long, with irregular edges. The sexual orifice, 

 which is mobile, may be alternately on the right 

 or left side. The uterus has a broad central body 

 and has five branches on either side, which are 

 intertwined. The eggs are oval and enveloped in 

 a tube-cast. The bladder-worm of the taenia mar- 

 ginata is the cysticercus tenuicollis, and is found in 

 the serous tissues of the sheep, cattle, goat, and pig. 

 Taenia Cuoumerina. {DipyUdium Caninum) 

 (Fig. 25.) is a small taenia from 5 to 30 cm. long 

 and 2 mm. wide. It has a small, elongated head, 

 with sixty hooks; the segments are rounded at the 

 corners and are the shape of a cucumber, and have 

 a small sexual orifice at each corner. The uterus is 

 irregular, with double-shelled, rounded eggs, six to 

 fifteen massed together in elongated cocoons. The primitive stage 

 of this tffinia, which is very common in the dog, is in the abdominal 

 cavity of the dog-louse (trichodectes eanis) (Melni- 

 koff) and also in the common dog-fiea (ceratop- 

 syllus eanis.) 



Tsenia Coenurus. (Fig. 26.) This taenia is 

 generally about 40 cm. long, although in rare 

 instances it may reach 1 m. It has a small, 

 pear-shaped head, with twenty-eight to thirty - 

 six hooks and four sucking disks. The anterior 

 links of the colony are always very short, and 

 those at the extreme end are elongated and nar- 

 row. The uterus has a long central body, with 

 eighteen to twenty-six side branches. The eggs 

 have a hard shell, with an indurated border. The 

 larval state of this taenia, which is the coenurus 

 cerebralis, varies in size from a small seed to a large egg, and 

 has a number of nursing or daughter-cysts or bladders on its 

 inner wall. It is generally located in the brain, and in rare 



Fig. 26. 



Taenia coenurus 

 (natural size). 



