328 



ANIMAL BIOLOGY. 



[Part II. 



Fio. 97. LIVER-FLUKE : EMBRYONIC STAGES. 



(After A. P. Thomas.) 



A. Ovum. em. Embryo, op. Operculum. 



B. Limnaeus truncatulus (natural size). 



C. Free Embryo. e. s. Eye-spot, ex. Excretory vessel, g. c. Germinal 

 cells, h. p. Head-papilla. 



D. Embryo preparing to become a sporocyst. g. c. Germinal cells. 



E. Sporocyst. g. Gastrula. m. Morula. re. Redia. 



F. Redia. 6. o. Birth opening, ce. Cercaria. col. Collar, di. Digestive 

 sac. ph. Pharynx, p. pr. Posterior processes, re. Daughter redia. 



G. Cercaria. cys. Cystogenous organ, di. Digestive sac. o. s. Oral sucker. 

 p s. Posterior sucker, ph. Pharynx. 



