FASCIOLA HEPATICA. 



167 



Leuckart could not clearly recognize the existence of a ciliated 

 covering, but on breaking the shell- walls the ingress of water soon 

 revealed the presence of a long wavy hne surrounding the entire 

 body. In an earUer stage I have myself observed distinct appear- 

 ances of segmentation of the embryo as well as other co-ordinating 

 phenomena precisely similar to those which Leuckart so minutely 

 describes. I was much puzzled, however, with certain appearances 

 which these eggs displayed on being broken up ; for along with the 

 embryo there escaped a number of amoeboid bodies, which moved 

 about actively. On showing my figures of them to Leuckart, he 



Tig. 37.—; 



of Fasciola hepatica, containing incxjmpleteljf developed embryos (x 300 diam.).- 

 Original. 



decided that they were parasitic confervoid zoospores, being, in all 

 respects, similar to those he had himself seen and described as re- 

 ferable to the genus Ghytridium. 



The structure of the embryo at the time of its escape from the 

 egg-coverings is exceedingly simple. It has the form of a long 

 cone inverted, the anterior extremity being flatly convex or almost 

 truncate, with a central proboscis-like papilla, devoid, apparently, 

 of cilia. The tail is bluntly pointed. The general ciliated cover- 

 ing rests on a well-defined, finely granular epidermis, the latter 

 being succeeded by a thick peripheral layer of large nucleated cells, 



