68 POULTRY DISEASES 



the feces and falls to the ground. Thus, at times, 

 we may find in the excrement of an infested bird 

 the segments, white in color and possessing the 

 power of movement; that is, it contracts and ex- 

 pands, showing it to be alive. This is especially 

 noticeable if the segments be placed in water. 

 Before it is detached each segment absorbs its 

 own nutrients through its integument. This nutri- 

 ent consists of the food eaten and digested by its 

 host as alluded to above. New segments are con- 

 stantly developed by the head of the tapeworm, 

 growing down, becoming ripe, i. e., filled with ma- 

 ture eggs, and detached; if not interfered with, 

 this process goes on almost indefinitely. 



Upon disintegration of the segments shed from 

 the worm, and passed out with the feces, the eggs 

 become scattered. The life history of the worm 

 from this state is not well understood. It prob- 

 ably has an intermediate host, by which the eggs 

 are taken up, and within which they pass through 

 a cystic stage and form embryos, which reach the 

 intestine of the bird, become attached and develop 

 to the adult stage. 



The larva consists of a head with its fixation 

 apparatus, namely, the suckers and booklets, if 

 such be present in the adult, and a neck. Having 

 attached itself to the mucous membrane of the in- 

 testines, it now absorbs digested food and begins 

 to develop segments, which in a few weeks begin 

 again to be shed at intervals, containing fully de- 

 veloped eggs, which number several hundred in 

 each segment. Under proper conditions, each egg 

 is capable of producing a single tapeworm as 

 before. 



