INTERNAL PARASITES 71 



Treatment. — The treatment should be the same 

 as for the T<snia infundibuliformis (which see), 

 or mix with the feed one teaspoonful of powdered 

 pomegranate root bark for every fifty adult birds. 



Other Taeniae 



Two or three other species of tapeworms closely 

 resembling these in their gross appearance have 

 been described, but judging from the records they 

 do not appear to be common. Tapeworms are 

 also found in the intestinal tract of ducks and 

 other birds. 



THE THORN-HEADED WORMS 

 (Acanthocephala) 



The third class of worms listed belong to the 

 order Acanthocephala. The body is cylindrical, 

 but they are not provided with a complete diges- 

 tive tract, as are the nematodes, or round worms. 

 They have transverse markings, and, like the tape- 

 worms, live by absorbing, through their integu- 

 ment, nutrients eaten and digested by their hosts, 

 thus robbing them to a certain extent. Further 

 more, when present in great numbers, these para- 

 sites cause digestive derangements and emacia- 

 tion of their hosts. They are provided with a 

 globe-shaped proboscis, armed with booklets, 

 which they embed in the mucous lining of the in- 

 testines ; thus attached by their heads, their bod- 

 ies float in the intestinal contents. 



Echinorynchus Polymorphus 



This is one of the three species of this genus 



that live in the intestines of the duck. It is also 



found in the goose. 



Description. The Echinorynchus polymorphus varies In 



length from one-fourth to one inch. The body is orange-red 



