1910.] ORGANS OF THE FISH CHIMERA MONSTROSA. 533 



function of the glands of Leydig is the secreting of a fluid for 

 giving nutrition to the spermatozoa. 



(3) The sexual kidney or " Geschlechtsniere " is represented 

 in the adult male only by the rete testes, efferent ducts, and 

 longitudinal collecting duct. Moreover, an epididymis, as usually 

 defined, is absent. 



(4) The development of the glands of Leydig is accompanied 

 by changes in the sperm-ducts, and the formation of highly 

 complex sperm-vesicles. 



(5) The anterior region of the urinary organ undergoes a 

 retrograde development, as is shown by a comparison of this 

 structure in the immature and adult females. 



(6) There is a distinct urogenital sinus in the young female, 

 which does not persist in the adult. 



(7) The application of the term " receptaculum seminis " to 

 the digitiform gland found ventral to the urinary bladder is 

 erroneous, and this structure must for the present be regarded 

 as a female accessory genital gland of obscure function. 



Literature. 



1. Leydig. — Zur Anatomie und Histologic der Chimaira mcii- 



strosa. Midler's Archiv, 1851. 



2. Hyrtl. — Ueber weibliche Oviducte bei miinnlichen ChimaBren, 



und eine mannliche Vesicula seminalis bei Weibchen. 

 Sitzungsberichte der kaiserlichen Akademie der Wissen- 

 schaften, 1853. 



3. Semper, C. — Das Urogenitalsystem der Plagiostomen und 



seine Bedeutung fiir das der iibrigen Wirbelthiere. 

 Arbeiten aus dem zool.-zoot. Institut in "Wiirzburg, 1875. 



4. Howes, G. B. — Reference to rudiment of vesicula seminalis 



in female Ckimcera. Linn. Soc. Journ., Zool. vol. xxiii., 

 1890. 



5. Mazza, F., and Perugia, A. — Sulla glandula digitiforme 



nella Ckimcera monstrosa, Linn. Atti Soc. Lig. di Sc. 

 Nat., vol. v. fasc. ii., 1894. 



6. Mazza, F. — Atti Soc. Lig. di Sc. Nat., vol. vi., 1895. 



7. Parker and Haswell. — Reference in Text-book of Zoology, 



(London), vol. ii., pp. 173-183, to testes, spermatophores, 

 vestigial Miillerian ducts. 1898. 



8. Redeke, H. C. — Onderzoekingen betreffende het Urogenitaal- 



systeem der Selachiers en Holocephalen. Acad. Proefschr. 

 Amsterdam, 1898. 



9. Redeke, H. C. — Kleine Beitrage zur Anatomie cler Plagio- 



stomen. Tijdschr. d. Nederl. Dierkund. Vereeniging, 

 1899. 



10. Jungersen, H. F. G. — Reference to claspers, Anat. Anzeig. 



vol. xiv., 1898. 



11. Jungersen, H. F. G. — On the Appendices Genitales in the 



Greenland Shark, Somniosus microcephalus, and other 

 Selachians. Danish Ingolf -Expedition, 1899. 



