A treatise on zoology . mayperhaps be seen in some lower forms. The sperm-ducts may openinto the base of the mesonephric ducts or bladder, as in Eels,Anahlejjs, Perca, Zoarces, Cyclopferus, etc.; or by a special opening,Clupea, Scarus, Trigla, Tinea, etc. ; or together with the anus, Lota ;or with both the anus and the kidney, Lophobranchii (Hyrtl,Stannius [417]). The urinogenital organs of the Teleostei present features whichare very difficult to explain and have given rise to much contro-versy (Rathke [342], Huxley [231], Waldeyer [478], Semper [404],Balfour [29, 30], Brock [59, 60], Weber [
A treatise on zoology . mayperhaps be seen in some lower forms. The sperm-ducts may openinto the base of the mesonephric ducts or bladder, as in Eels,Anahlejjs, Perca, Zoarces, Cyclopferus, etc.; or by a special opening,Clupea, Scarus, Trigla, Tinea, etc. ; or together with the anus, Lota ;or with both the anus and the kidney, Lophobranchii (Hyrtl,Stannius [417]). The urinogenital organs of the Teleostei present features whichare very difficult to explain and have given rise to much contro-versy (Rathke [342], Huxley [231], Waldeyer [478], Semper [404],Balfour [29, 30], Brock [59, 60], Weber [482], Jungersen [253]\, ^66 TELEOSTEI Haller [193], Howes, Felix [136]). We may here briefly discusstheir morphology. In both sexes the gonads arise as a longitudinalthickening of the coelomic epithelium, near the base of the mesentery,which hangs in the body-cavity as the genital ridge (Fig. 338).On the outer side of this fold the genital cells are developed. First of all with regard to the absence of a direct communi-. Fu:. 355. Diagrams of the friiiale urinosenital ducts in the Dipnoi and TeleostKures of various authors. A, Protoptcrus (after Ayers and W. N. Parker), stonii derived from theliKures of various authors. A, Protoptcrus (after Ayers and W. N. Parker). B, Polypteriis {afterBiid-ett). C, Amid (after Hyrtl and Huxley). D, Lepidosteus (after Balfour and Parker). B,a Teleost with closed F, a Sahnonid (after Weber), , abdominal pore ; c, cloacalbladder; d, cloaca;/, oi)eii funnel of oviduct; /,-, mesonephros ; , niesoneiihric duct; o,ovary ; od, oviduct; up, genital papilla and pore ; ovs, closed ovisac ; r, rectum ; , urino-genital papilla ; , urinary pore. In all the figures, except F, only the right oviduct is coiu-pletely drawn. cation between the testis and the mesonephros, characteristic of allthe Teleosts. This is doubtless secondary. A system of spaces andcanals develops from the testis, and from these is formed near thebase of the peri
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