722 JOHN BEARD, 



of two kinds, and, therefore, the male is never capable of becoming 

 hermaphrodite. 



A tabulation and discussion of several instances of supposed 

 hermaphrodite cod-fish have been given by Prof. G. B. Howes ^). From 

 his finds and from various considerations Howes comes to the con- 

 clusion, that the original Vertebrate stock was hermaphrodite. It is, 

 perhaps, needless to remark, that this is, and must be, erroneous. 



The conversion of hermaphrodites into dioecious forms, and of 

 males of dioecious animals into hermaphrodites are things believed 

 in, but hitherto without evidences of a reliable kind. The idea of 

 the original or primary nature of hermaphroditism was never founded 

 at all in facts, and with the lapse of time and the accumulation of 

 the results of research it has not emerged unscathed. In those in- 

 stances, where the relations of the hermaphrodite and dioecious states 

 to each other have been looked into, it has, as a rule, turned out, 

 that the former had been derived from the latter, and that in all cases 

 it was upon the females, that the hermaphroditism had been super- 

 imposed. This has now with greater or less certainty been established 

 in Cirripedia, certain Teleostei (Brock), Sacculina (Yves Delagb), 

 Mollusca (Paul Pelseneer), Mysostoma (the writer), Myxine (J. T. 

 Cunningham), and, lastly, various Nematoda (E. Maupas). 



Because of these facts and the now obvious correctness of the 

 conclusion, that only the female Metazoon can become functionally 

 hermaphrodite^ and because of the further consequence, that all 

 hermaphrodites must be altered females, the writer has not deemed 

 the inclusion of a special chapter upon hermaphroditism in this wri- 

 ting needful. 



In connection with the question the reader's attention may be 

 directed to the two following publications: 1) E. Maupas, Modes et 

 formes de reproduction des Nematodes (in: Arch. Zool. expér., V. 8, 

 1900, p. 463—624), and 2) Prof. Perrier's report upon Maupas' 

 researches in the competition for the "Grand Prix des Sciences phy- 

 siques" (in: CR. Acad. Sc. Paris, No. 25, 16 Dec. 1901, p. 1089 to 

 1096). 



In his extensive researches upon Nematodes Maupas confirms for 

 still another group the writer's conclusion of 1884 that "hermaphro- 

 ditism, probably all hermaphroditism, had its origin in a unisexual 



1) Howes, G. B., On some hermaphrodite genitalia of the Codfish, 

 in: Journ. Linn. Soc. London, Zool, V. 23, 1891, p. 539-558. 



