CONTEI^TS XI 



PAGE 



2. Tricladida. Oviposition ; yolk-cells ; cleavage . 169 



Formation of the embryo and its organs . . 169 



3. Khabdoccelidse 173 



[Acoela] l''ö 



General considerations : relation of the Tur- 

 bellaria to the Ctenophora (Ctenoplana and 



Coeloplana) 176 



II. Trematoda 178 



Composition of the egg from egg-cells and yolk-cells . 178 



1. Distomidse 1'° 



Embryonic development . . . ■ .1^9 

 Further course of development; Distomum 



hepaticum 180 



Sporocyst ; Redia ; Cercaria .... 180 

 Differences in the development of various 



Distomidse 18o 



Cercaria setifera, Bucephalus, Leuoochlori- 



dium, etc. 186 



2. Polystomidse 188 



Diplozoön, Gyrodactilus, etc 189 



III. Cestoda 190 



Character of the eggs ; resemblance to those of Tre- 

 matodes ......... 190 



Embryonic development of the Bothriocephalidse . 191 



Embryonic development of the Tseniadse . . . 193 



Further development; transference of the eggs; 



Cysticercus 194 



Formation of the scolex; transference of the Cysti- 

 cercus ; development of the tapeworm . . . 197 



General considerations : significance of the develop- 

 ment (Archigetes, Caryophyllseus, Amphiptyches, 



etc.) ' 198 



Taenia coenurus and T. echinococcus ; relation to the 



Trematodes (Amphilina) and Turbellaria . . 200 



Literature 201 



Chapter V. Orthonectid.e and Dicyemid.'e. By E. Korschelt 206 



206 



Orthonectidae 



Systematic survey ; occurrence ; shape of the body 



organization; eggs 

 Development of the male . 

 Development of the female 



II. Dicyemidae 



Systematic occurrence; organization 

 Development of the vermiform embryos 



207 

 208 

 209 



209 

 209 

 210 



Structure and development of the infusoriform embryos 211 



