436 Dr. Johnston on Entozoa. 



discover the exact nature of the connexion. On compressing 

 a specimen, the tail was suddenly thrust out like a concealed 

 proboscis, carrying the end of the ovary with it, as is repre- 

 sented at fig. 6 ; but this occurred only once, notwithstanding 

 many subsequent trials on other specimens. The course of 

 the ovarian tube is shown in fig. 5, but it is far from constant, 

 and in many specimens there is less of it than is there exhi- 

 bited between the sucker and the mouth, — in some none at 

 all. The duct is narrower at some places than at others ; is of 

 a dirty greenish colour, and composed of numberless ova, en- 

 veloped and imbedded in a colourless jelly; for the organ is 

 not hollow, as the term duct would seem to imply, but a fila- 

 ment formed of ova and jelly retained by a thin pellicle. When 

 examined separately the ova are of an ovate shape, pellucid, 

 with a speck in the centre, and in fact are very like the spo- 

 rules of parasitical fungi. I could not in any instance make 

 them separate and escape from the body without tearing the 

 skin ; but that they escape naturally by a minute aperture in 

 the emargination of the posterior extremity, I was led to con- 

 jecture from the circumstance just mentioned of the oviduct 

 being drawn down with it in its forced evolution ; but the con- 

 jecture is, perhaps, rendered improbable from its contrariety 

 to what occurs in other species. Mr. Owen in a large Distoma 

 (a generic name often used for the Fasciola) found that the 

 orifice in question formed the outlet of a glandular sac lodged 

 in the enlarged extremity (Cyclop, of Anat. and Physiology, 

 vol. ii. pp. 133 and 136); and Nordmann supposes that a si- 

 milar aperture in the Diplostomum is the termination of a canal 

 continued from the oviduct, a supposition which agrees well 

 with our observation. The ova, Cuvier says, * sortent par 

 un canal replie qui aboutit a un petit trou a cote de la verge f* 

 (Regne Anim. hi. 264.) Such an organ and canal I could not 

 discover in the species under examination. On each side of 

 the sucker, and usually behind it, there is a large roundish 

 viscus of a milk-white colour, apparently unconnected with 

 either the ovary or intestine, although it is probable that a 

 connexion does really exist. They are also supposed to be 

 connected with the generative functions ; and of the same na- 

 ture we are told is a similar viscus situated nearer the middle 



