15 



being called the uterus, be considered as a part of the 

 ovaries. It is apparently of the same texture as 

 the ovaries; its functions appear the same. Why then 

 call it a uterus, when it is not destined to contain the 

 embryo at all, but is continually filled with eggs, 

 which are generally more developed here than in its 

 branches ? I would therefore consider it as a portion 

 of the ovary, not as a separate organ, and look upon 

 the Tsenia as destitute of any true uterus. 



No visual or respiratory organs have been dis- 

 covered in this parasite ; and it seems, a priori, that 

 there should be none, as it lives in closed cavities 

 or dark recesses, where there would be no occasion 

 for them. 



Starting from the sucking discs are seen four little 

 filiform canals. These unite and form two, one on 

 each side, which run down along the margins of the 

 entozoon; uniting at the posterior border of each 

 joint by transverse canals. These lateral canals pos- 

 sess valves, which prevent their fluid contents from 

 regurgitating (Moquin-Tandon). Weinland does not 

 consider that they unite, but remain separate ; all 

 four finally meeting in the head of the worm, in a 

 vascular ring, round the proboscis. 



This has been considered as the nutritive system of 

 the Tsenia; its contents consist of a watery fluid 

 (Weinland). 



No anal orifice has been observed. 



With regard to the circulatory apparatus, M. 

 Blanch ard described four thin longitudinal canals, 

 two on each aspect, communicating by means of 



