46 ON HERMAPHRODITISM IN AN AMPHIPOD. [Jan. 14, 



Among Vertebrates they occur normally at certain periods in 

 the testes of Petromyzon^ Scumio, and numerous amphibians (ajoart 

 from the problematical " organ of Bidder " in Bufo). It is inter- 

 esting to find that in most of these cases the production of ova is 

 limited to the developing or regenerating testes, and for this 

 reason I will enter on a few more details about such forms. 



Thus R. Hertwig (9) has recently given an account of his 

 observations on the sexual organs of young tadpoles. In this 

 paper he practically confirms the theoretical conclusion, first 

 arrived at by Pfliiger, that the surpKis of females which con- 

 stantly occurs in broods of tadpoles is due to a more or less 

 developed tendency to hermaphroditism in the males at this 

 stage ; some of the so-called females proving to be males at a 

 later stage in their development. 



Lubosch (10) has obtained practically the same results from his 

 -studies of the sexual organs of the larval Petromyzon. 



To take yet another example. Felix (11), describing the deve- 

 lopment of the testis in Salmo, calls attention to the " aufFallende 

 Thatsache das alle von mir untersuchten jungen Mannchen von 

 Scdmo solar in dem vorderen Abschnitt ihrer Genitaldrlise 

 vollstiindig ausgebildete Eier zeigen." 



It seems then that the phenomenon described by me in Orchestia 

 deshayesvi is not an unusual one, and finds a parallel in many 

 other animals ; its significance and its relation to the various 

 theories formulated to explain such cases of hermaphroditism 

 I cannot discuss here ; I will merely refer the reader to the 

 excellent paper on this subject by Stephan (12), in which will be 

 found a lengthy discussion of the current theories bearing upon it. 



Bibliography. 



(1) Nebeski, 0. — " Beitrage zur Kentniss der Amphipoden der 



Adria." Arb. Zool. Inst. Wien, torn, iii., 1880. 



(2) Bella Valle, A. — " Gammarini " in ' Fauna u. Flora Golf. 



Neapel,' Monograph 20, 1893. 



(3) Smith, Geoffrey.—" Rhizocephala." Ibid., Mon. 29, 1906. 



(4) Barrois, Th. — " Notes sur quelques points de la Morphologie 



des Orchesties." Lille, 1887. 



(5) Krohn, a. — " Zur naheren Kentniss der mannlichen Zeug- 



ungsorgane von Phcdangium." Arch. f. Nat. 1866. 



(6) Garnier, C. — " Hermaphroditisme histologique dans le tes- 



ticule adulte ([\istaGus JiicviatiUs." 0. R. Soc. de Biol., 

 1906. 



(7) IscHiKAWA, C. — " On the formation of Eggs in the Testis 



of Qebia major." Zool. Anz. xiv., 1891. 



(8) Potts, F. A. — " The Modification of the Sexual Characters 



of the Hermit Crab caused by the parasite Peltogaster." 

 Q. J. M. S. vol. 50, 1906. 



(9) Hertwig, R. — " Weitere Untersuchungen, &c." Yerh. d. 



Deutsch. Zool. Ges., 1906. 



