APPENDIX V 

 REPRODUCTION 



A. HERMAPHRODITISM OF THE APODID^E. l 



(From Naitire, vol. xliii. p. 343.) 



THE reproduction of Apus cancriformis has been a much 

 discussed subject. Although the animal has been well 

 known since the middle of last century, it was not till 1833 

 that a male was reported to have been found, and not till 

 1856 that the occasional presence of males in small numbers 

 was certainly established by Kozubowski. On the other 

 hand, the fact that several generations of "females" could 

 be produced without the presence of a male, was established 

 as long ago as 1755 by Schaeffer, who concluded that the 

 animals were hermaphrodite. Since that time authors have 

 been divided in opinion between hermaphroditism and 

 parthenogenesis (not to mention v. Siebold's theory of 

 Thelytoky) ; the latter view has lately prevailed. 2 



1 The letter here reprinted was written before the author had 

 recognised the Annelidan character of Apus which led to the writing 

 of this book ; hence its point of view is not altogether the same as that 

 of the foregoing pages. 



2 For the history of this subject see Bronn's Klassen und Ordnungen 

 des Thierreichs, vol. v. On p. 810 the following words occur : 

 " Untersuchungen iiber die Gattungen Apus und Daphnia, welche 

 offenbar in dem bis zu voller Evidenz gefuhrten Nachweis der partheno- 

 genetischen Fortpflanzung beider gipfeln." See also Lang's Lchrbnch 

 der Vergleichendc Anatomic, p. 393. 



