3. On the Hermaphroditism of Fixed Auimals. 105 



into separate sexes, it is manifestly bound up in the majority of animals with widely different 

 habits of life, so tbat the males and females of most species fili a different róle in the economy 

 of their species with regard to almost every vital fnnction besides that of reproduction. In 

 fixed animals which are by the fact of their fixation destined to a more or less dull routine 

 of existence in which the vital functions have only to perforai a few stereotyped duties, this 

 elaborate differentiation of the sexes has been lost. In this manner we may look upon the 

 hermaphroditism of fixed animals as part of the general degeneration which they have mani- 

 festly undergone in ali other respects. 



Without entering further here into a subject which formed the chief theme of the last 

 chapter, I would emphasise that point of view which regards the sexual organization of every 

 animai not merely as an adaptive means of propagation, but also as a regulation of the meta- 

 bolic activities in the animai itself, irrespective of the production of a new generation. The 

 phenomena of sex are so intimately bound up with those of assimilation, growth and differen- 

 tiation, that we cannot hope to gain any complete explanation of their variations in different 

 animals by simply regarding them as a mechanism for ensuring the production of young, while 

 ignoring their relation to the metabolic activity of the body which exhibits them. 



List of Literature. 



1. Fraisse, P., Die Gattung Cryptoniscus. in: Arb. Z. List. Wiirzburg 4. Bd. 1878. 



2. Mayer, P., Carcinologische Mittheilungen. 6. Ùber den Hermaphroditismus bei einigen Isopoden. in: 



Mitth. Z. Stat. Neapel 1. Bd. p. 165 1879. 



3. KoSSmaDIl, R., Neueres ùber Cryptonisciden. in: Sitzungsb. Akad. Berlin p. 547 1884. 



4. fflaupas, E., Modes et formes de ieproduction des Nématodes. in: Arch. Z. Expér. (3) Tome 8 p. 463 1900. 



5. Bonnier, J., Contribution à l'étude des Epicaridés. in: Trav. Stat. Z. Wimereux Tome S 1900. 



6. Hansen, H. J., Isopoden, Cumaceen und Stomatopoden der Plankton-Expedition. Kiel und Leipzig 1895. 



7. Caullery, M., & F. Mesnil, Recherches sur YHemioniscus balani, in: Bull. Se. France Belg. Tome 34 



p. 316 1901. 



Zoo]. Station zu Neapel, Flora und Fauna, Golf von Neapel. Khizocephala. 14 



