12 S. GOTO. 



the continued existence of the original epidermis. Besides, the 

 differentiation of the investing membrane into the true cuticle and the 

 suhcuticle, and the negative fact that, although I have directed my 

 special attention to the point, I have utterly failed to observe those 

 subcuticular glands so beautifully drawn by Brandes in his figures 

 in the very same genera that he describes, strongly incline me to the 

 view that the investing membrane of the ectoparasitic Trematodes is a 

 transformed epidermis. I have indeed observed some cells in the 

 ectoparenchyma which had the appearance of a gland (PI. XXI, fig. 

 4), but I have not been able to find out any duct, and believe them to 

 be cells of the mesenchyma and will therefore describe them under 

 that head. From his statements on p. 565 (op. cit.'), I gather that 

 Brandes regards the muscular fibres described by Poirier'^ in some 

 species of Distomum as the ducts of the subcuticular glands ; but 

 Poirier's figure in question is so clearly drawn that I doubt whether 

 one is justified to put another interpretation on it unless he has studied 

 the very same species. In Brandes' figures the muscular fibres and 

 the ducts of the subcuticular glands are distinguished by different co- 

 lours, but according to my own experience it is very doubtful whether 

 such difference in colour reaction exists really in nature. Moreover the 

 ducts of the subcuticular glands are drawn so fine in Brandes' 

 figures that one would be tempted to regard them also as muscular fibres 

 if they were coloured alike; and for my own part I do so regard them. 

 In this connection it may be mentioned that on examining once a 

 series of sections of Hexacotyle grossa which were somewhat overstained, 

 the terminal portions of the dorso-ventral muscular fibres were so 

 deeply stained that they looked just like the efferent ducts of some 



1). Poirier — Contribution a I'histoire naturelle des Trematodes. Archives de Zool. exper.-, 

 2. serie., T. Ill, 1883. 



