NEW HUMAN CESTODE. 



83 



rroin the investigations of Knoch, of Leuckart, and of Drs. 

 Bertolus and Duchamp, we know that the six-hooked proscoleces 

 of these worms are developed within a ciliated sphere. Thus, 

 Dr. Bertolus proposed that we shoiild call the proseoles the 

 embryo proper, employing his new term emhryopliore to de- 

 signate the free-swimming, ciliated, nurse-like embryo. It is 

 certain that ponds and streams frequented by water-birds in- 

 fested with ligules must contain multitudes of these ciliated 

 embryos, and thus (with the explanations already offered as to the 

 genetic relations of the Bothriocephali) we have not far to seek 

 for the cause of infection of dogs and men by the broad tape- 

 worm. In like manner the drinking of any open waters that 

 happen to contain these ciliated larvsB might also bring about 

 infection by ligules. In this way I think we may account not 

 only for the occasional introduction of Ligula reptans into the 

 muscles of various mammals, birds, and reptiles, but also for the 

 solitary instance in which a Chinese water-drinker shared with 

 these animals the privilege of harbouring a similar cestode 

 guest. 



^. 



Explanation of Figures. — Two examples of Ligula Mansoni. A, as seen from 

 before ; B, from behind (slightly enlarged from spirit specimens) ; C, papilla of 

 the head ( X 15 diam.) ; D, end of the papilla, showing cephalic pit and cal- 

 careous corpuscles. The last figure reduced from a drawing by Dr. Manson 

 (magnified about 80 diam.). 



