484 Protandric Hermaphroditism in the Mollusc, etc. 



case that it is the male which possesses the potentialities of both sexes. 

 A solution to this problem is offered, if, as seems likely, allied species present 

 an evolutionary series in the acquisition of protandric hermaphroditism. 



I wish here to express my thanks to the College authorities for the 

 facilities afforded me during the research. I am also deeply indebted to 

 Prof. Dendy and Mr. Darbishire for important suggestions and valuable 

 criticisms. 



EEFEEENCES. 



(1) Dodd, ' Malacological Soc. Proc.,' vol. 1, 1893, pp. 31, 32, and p. 19. 



(2) Conklin, ' Journ. of Morphology,' vol. 13, 1897, pp. 10—25. 



(3) Haller, ' Morphologisches Jahrbuch,' vol. 18, 1892, p. 514. 



(4) Smith, 'Fauna and Flora of the Gulf of Naples,' Monograph XXIX, 1906, 



"Ehizocephala," pp. 91, 92. 



(5) Conklin, 'Acad. Nat. Sci. Philadelphia Proc.,' 1898, pp. 438, 441, 442. 



(6) Pelseneer, Lankester's ' Treatise of Zoology,' vol. 5, 1906, ' Gastropoda,' pp. 124, 125. 



(7) Koehler and Vaney, ' Eevue Suisse de Zoologie,' vol. 11, 1903, p. 36. 



(8) Bonnevie, 'Zool. Jahrbuch. Anat. und Ontog.,' vol. 15, 1902, p. 735. 



