THE TAPE- WORM {Taenia) 



Various species of tape-worms are parasites in the alimentary canal of 

 Vertebrates. Two of the commonest species are Taenia serrata, which is foimd 

 in the dog, and Taenia or Dipylidium caninum, which is found in the dog and 



Young 

 Proglottides 



' Head " 

 Scolex 



Proglottides 

 approaching 

 maturity 



Ripe or Gravid 

 Proglottis 



Fig. 16.— The Beef Tape-worm (Taenia saginata). Selected 

 portions of a single specimen. After Leuckart. 



also in the cat. Portions of these tape-worms are generally discharged with the 

 f£eces of the host, and thus may easily be obtained. Complete specimens may 

 be procured by cutting open the intestine of dogs or cats which have been 

 destroyed. 



Form and General Structure. 



The Tape-worm has the form of a long segmented ribbon. Towards the 

 anterior end the ribbon becomes much narrower, and at this end the extremely 



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