T.€NIA 



87 



been found by Lesbre in the brain of a dog affected by taenia serrata. 

 This was probably caused by self-infection. This animal exhibited 

 symptoms resembling rabies, and was incessantly grinding the teeth and 

 snapping the jaws. 



Taenia Marginata (Fig. 43). — This is the longest and widest tsnia 

 of the dog, being 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 rounded with four small sucking disks 

 and a double crown of 36 hooks. The segments are nearly square. In 

 the middle of the colony they may even be broader than long, with ir- 

 regular edges and partially overlap the following section. The sexual 

 orifice which is situated on the margin may be alternately on the right 



Fig. 44. — Taenia cucumerina, Dipylidium caninum. 



or left side, the right sections are longer than their width, which are 14 to 

 1(3 mm. and 5 to 7 mm. wide. The uterus has a short central body and 

 has five branches on either side, which are intertwined. The eggs are 

 irregularly round and enveloped in a tough thick shell. The bladder 

 worm of the taenia marginata is the cysticercus tenuicoUis, and is found 

 in the serous tissues of the sheep, cow, goat, pig, squirrel, and monkey 

 in captivity, and occasionally in man (Dewitz). Frequently we find 

 the cysticercus on the peritoneum and liver of the sheep and pig, vary- 

 ing in size from a pea to the size of a man's fist. 



Taenia Cucumerina (Dipylidium Caninum) (Fig. 44). — This is a 

 small taenia 10 to 40 cm. long and 3 mm. wide. It has a small elongated 

 head, with sixty hooks with a retracted mouth or proboscis; the seg- 



