PLATE 2 



EXPLANATION OF FIGITRES 



3 View combined from sections of a sagittal series, showing together organs 

 wliich are on different levels, mouth, ventral sucker, genital organs and excretory 

 pore are median while the intestine and the collecting and recurrent excretory 

 vessels are lateral. X 27. 



4 Sections from a transverse series. The numbers show the number of the sec- 

 tion in the series; ^4 is in the level of the oesophagus; B, in front of the ventral 

 sucker; C, at the ventral sucker; D, at the uterine sack; E, at the genital pore; 

 F, at the anterior testis; G, at the canal of Laurer. From heron, corrosive and 

 acetic, iron-haematoxylin. X 27. 



5 The center section of a sagittal series, from a worm which died with the oral 

 fiehi inverted. Heron, after chromic acid fixation and iron-haematoxylin. X 40. 



22f) 



