109 
j 
I It has not been proved experimentally that the larvae fonnd bj^ 
i Mrazek or Dadai represent the intermediate stage of Ilymenolejns 
I lanceolata; but, upon the assumption that the}" or similar larvae belong 
to the life-cycle, it may be presumed that infection occurs as follows: 
The embryos of the tapeworm are distributed in stagnant pools b}^ 
129 130 
Fig. 126.— Cercocystis of [?] 11. lanceolata Avith scolex retracted. Enlarged. (After Dadai. 1900a, 
pi. 10, fig. 9.) 
Fig. 127.— Cercocystis x>f [?] II. lanceolata with scolex retracted. Enlarged. (After Dadai, 1900a, 
pi. 10, fig. 7. ) 
Fig. 128.— Cercocystis of [?] II. lanceolata scolex protruded. Enlarged. (After Dadai. 1900a, 
pi. 10, fig. 11.) 
Fig. 129.— Section of Avail of cercocystis of [?] H. lanceolata. Enlarged. (After Dadai, 1900a, pi. 10, 
fig. 12.) 
Fig. 130.— Hooks of cercocystis of [?] II. lanceolata. Enlarged. (After Dadjii, 1900a, pi. 10, fig. 8.) 
infected ducks or geese, and are ingested, whether liefore or after 
hatching is not known, liy Cyclops^ Diaptomtui^ or other small Crusta- 
cea, in the bod}" cavity of which the intermediate stage develops. The 
intermediate stage is introduced into the alimentary canal of some 
animal, normally a duck or a goose, by the drinking of water contain- 
126 
