ON DIPLOZOON XIPPONICUM, N. SP. 183 



The Female Organs — The ovary (Fig. 2, ov) is a long conico- 

 cjdindrical body which is doubled on itself by its middle portion, so 

 that the two ends come close to each (jther, and placed on the dorsal 

 side of the body just anterior to the testis, to which its smaller end 

 is closely applied ; the anterior end where it is doubled on itself 

 reaching as far as where the dorsal jjapilla formerly was. From its 

 larger end, wdiere ripe ova are found, proceeds the oviduct. As we 

 approach the other end, the ova become smaller and smaller until 

 finally we see a mere assemblage of round nuclei imbedded in a com- 

 mon mass of protoplasm. The whole ovary lies in a mere cavity of 

 the mesenchyma without any distinct wall of its own. A section 

 through the larger end (Fig. 21) shews the ovary to be a solid 

 body consisting of large ova which are either polygonal or wedge- 

 shaped according to the direction of the section. Each ovum is des- 

 titute of any membrane, and consists of a mass of homogeneous deeply 

 stained protoplasm, in which lies a large vesicular nucleus provided 

 with a distinct wall and containing a hyaline fluid in which float 

 numerous deeply stained dots, the chromatin {)articles. Each nucleus 

 again encloses a large deeply stained nucleolus in which are again to 

 be observed one large or a few smaller vacuoles. Zeller^' mentions 

 and figures in the ovum of Pokjstomum and Diplozoon a thick, elastic 

 " Hiille " ; but I have no doubt that the ovarian ova of Diplozoon are 

 destitute of any membrane. This is also the case in Axine, Micro- 

 cotijle. Octohothrium, Dactylocjijrus^ in fact in all the species of ectopara- 

 sitic Trematodes I have hitherto examined. Willemoes- Suhm^' men- 

 tions no '' Dotterhaut " in I'ohjstomuin occllatam, ; Taschenberg"^* asserts 



1) Zeller— Ztschr. f. w. Z. Bd. XX 11. p. 5 & 169 foot-note; Bd. XLVI. p. 235. Is not the 

 elastic membrane the result of fertilisntion? 



-) Wiilemoes-Sahui — Zur Naturgescn. d. Polyst. integerrimvim u. Polyst. ocellatum. 

 Ztschr. f. w. Z. Bd. XZII. 1872. p. 33. 



^) Taschenberg — Beiträge, p. 36. 



