T. B. R0SSETER ON HYMENOLEPIS FARCIMINALIS. 307 



cone is seen to be bi-papillated. Whether, however, there is an 

 orifice or channel leading into the embryonic space through the 

 indentation of the poles, I am unable to say. The perfect embryo 

 or six-hooked brood is plano-convex. It gastrulates at its planular 

 or ventral end, the embryonic hooks lying equidistant in the 

 gastrula cavity. In the early uterine stage, and also after the 

 development of the six-hooked brood, the third envelope is scarcely 

 perceptible — in fact, very difficult to discriminate ; but in those 

 segments, as in Fig. 1, /, which are ripe for segregation the 

 embryo lies free in the cavity (Fig. 4, e), its homogenity — due to 

 the using up of the nutritive cells — causing it to occupy a smaller 

 space in the capsule. In these segments a remarkable number 

 of ovarian or unfertilised eggs are mingled in the uterus with the 

 hexacanth or six-hooked brood. 



In conclusion, the following question may be asked : " What 

 character can we draw from structural details which may be used 

 as a criterion by future investigators in determining this species 

 of tape-worm as Goeze's T. farcimiaalis in specimens lacking the 

 scolex, hooks, and sausage -formed proglottides?" 



It would be waste of time and space, and, in fact, misleading, 

 to discuss the proposition on the basis of external structures 

 alone, and therefore we must seek some other salient point of the 

 internal anatomy which will enable us to determine a portion of 

 the strobila, or even a single segment, generically and specifically. 



(1) Generically. — The sexual pores are marginal, secundae, or 

 unilateral, situated on the left of each succeeding segment. That 

 of the male is dorsal, whilst the ventral is occupied by the female 

 genital apparatus. There are three testes, one proximal and two 

 distal, in the segment. The segments, being thus constituted, 

 would fall within the genus Jlymeuolepis, Weinland. 



(2) Specifically. — There are some minor peculiarities and points 

 in connection with the genitalia which might be enumerated to 

 assist the investigator in the diagnosis of this worm ; but there 

 is one portion of the female genitalia which, I think, should set 

 at rest any doubt in determining specifically any detached or 

 isolated proglottides as being a portion of the strobila of H.far- 

 ci/iiinalis, viz. the receptaculum seminis. 



