SO NATURE STUDIES. 



from the damp meadows, or from the water itself, 

 the sheep obtain these little beings. Once within 

 a sheep's stomach, each Cercaria seems to waken up 

 to its ultimate destiny. It drops its tail, and bores its 

 way through the tissues of the sheep towards the liver, 

 where it soon appears as the young fluke, which will- 

 develop eggs that will repeat its own curious history. 

 The most notable fact, however, of this development 

 is that if a sheep swallowed the egg of the fluke, no 

 development would ensue. The egg requires to pass 

 through its water-snail stage, ere the sheep can obtain 

 the new fluke. 



It is much the same with the tapeworm tribe as 

 with the fluke. The common tapeworm of man 

 (Tcenia Solium) consists of a very minute "head," 

 attaching itself by suckers and hooks to man's in- 

 testines; of a slender "neck," and of hundreds of 

 "joints." Each "joint" is really a semi-independent 

 animal; and the tapeworm is therefore a compound 

 animal, and presents us with a colony of similar beings. 

 A large tapeworm may measure 20 or 30 ft.; and new 

 joints are continually being " budded " out from the 

 head and neck. Hence the physician can never be sure 

 that he has cured a case of tapeworm until he has seen 

 the head and neck of the animal. If a man swallowed 

 the egg of a tapeworm, he would not be infested 

 thereby. The young worm has to pass its early life 

 in the body of another warm-blooded animal ; and in 

 the case of a common tapeworm, it is "the gintleman 

 that pays the rint," which acts the part of nurse or 



