OUK DOMESTICATED ANIMALS. 



97 



worm. There may be from three to five hundred of these 

 heads projecting from the surface of a single gid hydatid. 

 That each process does really represent the head of a 

 young tapeworm is not only proved by the evidence 

 derived from microscopic examination of the processes 

 themselves, but also by the results of our worm- 

 feeding experiments. 



Professor Simonds and myself have repeatedly reared 

 gid tapeworms from the gid hydatid ; and those who are 

 interested in the details of the method employed will find 

 an acconut of the experiments in the fifth article of the 

 supplement to my work on " Entozoa.'" 



Fig. 20. Tapeworm-like Heads of the Gid Hydatid 



If a small fragment of the gid hydatid with its charac- 

 teristic processes be magnified about eighty diameters, all 

 the more essential structures will be brought into view. 

 As in the accompanying drawing (Fig. 20), such a demon- 

 stration may display a bunch of young tapeworm heads, 

 one or all of them showing the crown of hooks (a), the 

 four suckers (b) } and a multitude of minute oval, calcareous 



H 



