642 MR. F. E. BEDDARD ON 



middle of the interior of the «colex into oval chambers lined by 

 an equally thick cuticle. Fui'ther down the canals lost their con- 

 nection with the exterior and were T-«haped, with still a very 

 thick cuticular lining and no recognisable sucker structure. This 

 canal in each of the four quarters of the scolex continued for 

 some sections without any change, and then the suckers themselves 

 became plainly visible, being thus entirely retracted within the 

 scolex aiid removed from the extei'ioi-. The cavity of the suckers 

 is here triangular, with the sides closely pressed together. The 

 outlines of each suckei- ai-e sharply mai'ked oft' fi'om the sui-- 

 I'ounding tissue of the scolex by a layer of black pigment granules, 

 which pigment is also found in the central portion of the scolex. 

 The lining cuticle of the suckers is much thinner than that which 

 covei's the scolex, and lines the canal of invagination leading to 

 the suckers. The outline of the scolex is here appi'oximately 

 circvilar. 



The generative organs are visible in an immature condition 

 very early in the body, though I have not made an accurate deter- 

 mination of the exact segment in which they first occur. At first 

 I could find no trace of any testes, simply a. mass of geneiutive 

 blastema which occupies the position of the future ovaries, 

 vitelline gland, and shell-gland, fi'om which leads a solid rod hardly 

 narrower towards but not to the edge of the proglottid ; this latter 

 is, of course, the vagina, etc. This mass of tissue lies just anterior 

 to the transverse vessel, uniting the two ventral excretoiy vessels, 

 and is therefore some Avay from the posterior boundary of the 

 pi'oglottid. In transverse sections tlu'ough these very anteiior 

 and immature proglottides it is seen to lie upon the ventral side of 

 the ti'ansverse vessels and to cross it obliquely to the dorsal side, 

 whence it passes towards the edge of the proglottid to the dorsal 

 side of both dorsal excretoiy tube and nerve. This is the same 

 on both sides of the body, the generative organs being single and 

 alternate in this worm. 



Only a segment or two further back than those just described 

 the testes become visible, though, of course, at first quite immature. 

 They form a row generally only one deep (when viewed in longi- 

 tudinal horizontal section) extending from the excretory tubes of 

 one side of the body to those of the other. I counted about fifty 

 small testes in such a row. Here and there the row is two deep. 

 1 could detect no trace of the vas deferens. The row of testes was 

 anterior to the I'udimentary female oi-gans. These latter are by 

 this time somewhat more developed. They still present, however, 

 a perfectly straight line, but reach very neai-ly to the edge of the 

 proglottid. There is, however, no extei-nal aperture. The fact 

 that the vagina is a tubular foi'mation is beginning to be evident, 

 and the shell-gland, with radiating cells, in which it ends is plain ; 

 the ovary and vitelline gland lie below it and thus not in the 

 same plane with the vagina. 



The female oi'gans extend ovei- moi-e than a quai-ter, but not 

 quite a third, of the diameter of the proglottid. In still later 

 proglottides the uterus is for the first time quite visible and can 



