608 



AMERICAN MUSEUM OF NATURAL HISTORY 



TJrinogenital Syst. — Cont'd. 

 PETROMYZONTES 

 Excretory Organs 



In the lampreys, the pronephros is most de- 

 veloped and functional in the larval Ammocoetes 

 of 10 mm. length. The mesonephros is like- 

 wise functional in this stage and later develops 

 to extend over about two-fifths of the body 

 length. 



Structure and development of the excre- 

 tory organs in Petromyzon. Bujor, P. 

 1891.1; •Hatta, S. 1897.2, 1900.1; 



Meyer, F. 1876.1; Miiller, J. 1834.1 (v); 

 Miiller, W. 1875.1; Regaud, C. & Poli- 

 card, A. 1901.1; Vialleton, L. 1890.1; 

 •Wheeler, M. W. 1899.1. 



Urinogenital system of 

 Dipnoi 



Genito-urinary organs of breeding males 

 of Lepidosiren and Protopterus. -ArKerr, J. 

 G. 1901.1. 



Urinogenital system of Lepidosiren and 

 Protopterus. Ehlers, E. H. 1895.1; Kerr, 

 J. G. 1902.2; Parker, W. M. 1888.2; 

 Semiohon, L. (Ovary) 1913.1. 



Pronephros of Neoceratodus, develop- 

 ment. •Semon, R. W. 1901.3,.4,.6; 

 WUson, G. 1901.1. 



XTrinogenital system of 

 Elasmobranchii 



The most comprehensive treatise on the 

 urinogenital system of the Elasmobranchii 

 (text in French), including a review of the 

 literature, is *Borc6a, J. 1905.1. 



A scholarly treatise in German, on the 

 development of the urinogenital system of 

 Selachii, is -A-Rabl, C. 1896.1. 



Other papers on the development are 

 •Balfour, F. M. 1874.1, 1876.2, 1878.2; 

 •Rilckert, J. 1888.2, 1889.2; •Semper, 

 G. G. 1874.1-1875.3, Add. 1874.1 ; •Wijhe, 

 J. W. 1888.1, .2, 1889.1. 



PLAGIOSTOMI 

 Reproductive organs 



Structure and development of the ovary in 

 Selachii. Balfour, F. M. 1878.3; Giaco- 

 mini, E. 1894.1, 1896.1; Rathke, M. H. 

 1827.1. 



Ovarian follicle and corpus luteum of 

 Spinax. Wallace, W. 1903.1. ■ 



Mechanism of hymen in Plagiostomes. 

 Widakowich, V. 1908.1. 



Older papers on the structure of the testis 

 in sharks and rays. Hallmann, E. 1840.1; 

 Martino, A. 1848.1; Miiller, J. 1831.1; 

 Stannius, F. H. 1840.1. 

 . Miscellaneous early papers on the re- 

 productive system of sharks, references in 

 Pre-Linn. section. Belon, P. 1551.1; 

 Collins, S. 1685.1; Duverney, J. G. 

 1733.2; Klein, J. T. 1740.1 (iii); Steno, 

 N. 1675.1. 



For an old but extensive account of the 

 reproductive organs of Plagiostomes with 

 an excellent review of the old literature, see 

 Tilesius von Tilenau, W. G. 1802.1. 



For the structure of the oviduct in adult 

 Selachii, see Uterus below Viviparity under 

 Reproduction. 



For the manner of formation of the horny 

 egg-cases of Elasmobranchii through secre- 

 tion by the nidamenial gland of the oviduct, 

 see below Egg-cases under Ova and ovum. 

 Excretory organs 



Older papers on the structure of the ex- 

 cretory organs in Selachii. Hyrtl, C. J. 

 1861.3; Meyer, F. 1875.1; Miiller, J. 

 1842.1, .3; Steenstra-Toussaint, A. 



1834.1-1839.2. 



Morphology of mesonephros in numerous 

 forms, Notidanus, Centrina, etc. Borcea, 

 J. 1904.1-1905.2. 



The pronephros is never functional as 

 an excretory organ. 



Development of pronephros in Chlamydo- 

 selachus, Acanthias, and Scyllium. Broh- 

 mer, P. 1908.1; Haller, B. 1901.1; La- 

 guesse, G. E. Add. 1891.3; Burlend, T. 

 H. Add. 1914.1. 



Occasionally, because . of the influence of 

 other viscera, there are variations in size; 

 a dwarfed kidney may occur on one side, 

 as recorded in Raja by Howes, G. B. 

 1890.4. 



Although usually obliterated during de- 

 velopment, as first noted by Semper, (en- 

 tonnoirs segmentaires) open peritoneal 

 funnels (incorrectly called nephrostomes) 

 may persist throughout life in certain 

 sharks such as Cestradon, Scyllium cani- 

 cula, S. stellare, Pristiurus, Spinax niger, 

 Acanthias vulgaris, Scymnus lichia, Cen- 

 trina salviani, and Rhina squatina. 



Structure and arrangement of the open 

 peritoneal funnels. Borcia, J. 1905.1; 

 •Guitel, F. 1897.1, 1900.2; Schneider, G. 

 1897.1; Semper, C. G. 1874.1-1875.3. 



Bles believes that when the peritoneal 

 funnels persist, the abdominal pores tend 

 to be reduced and vice versa. •Bles, E. J. 

 1898.1, .2. 



Cloacal cavity of some Selachii, anatomy. 

 Savoure, P. 1910.1. 



In male Elasmobranchs, the anterior 

 end of the mesonephros is glandular and 

 entirely lacking in Malphigian corpus- 

 cles. It secretes a whitish fluid, variously 

 considered to supply a nourishing medium 

 for the spermatozoa or (in Chimcera) to 

 dissolve the investments of the sper- 

 matophores. It is known as Leydig's 

 gland. 



Structure and functions of Leydig's 

 gland in sharks. Borcfea, J. 1904.1, .6, 

 1905.1; Disselhorst.R. 1904.1; Morgera, 

 A. 1909.1. 



HOLOCEPHALI 



In ChirruBra the gland just mentioned 

 was first described as a " Nebenhoden," in 

 Leydig, F. Add. 1851.1. 



By Hyrtl, it was named Leydig's gland. 

 Hyrtl, C. J. 1854.3. 



Other papers describing this gland or the 

 urogenital system of Chimcera, are •Bur- 

 lend, T. H. 1910.1; Parker, W. N. & 

 Burlend, T. H. 1909.1; Redeke, H. C. 

 1898.1. 



Reproductive organs of Chimcera, es- 

 pecially ovaries and oviducts. •Dean, B. 

 1906.1. 



