574 



John Beard 



deucy towards hermaphroditism, the embryonic sexual cells of one or 

 more segments may become spermatozoa instead of ova, or vice versa. 



Again it should not be forgotten that most hermaplirodites bave 

 very complicated sexual duets etc. , wbich are obviously uot primitive 

 organs but adaptations designed in most cases to bring about cross fer- 

 tilisation and prevent self-impregnation. Such duets could only arise in 

 pretty bigbly developed forms, tbat is to say could only be converted 

 to secondary sexual uses in cases in wbich they really were present 

 beforehand, and hence only in pretty highly developed forms. This 

 circumstance points rather to a developing hermaphroditism which arose 

 pari passu with the conversion of these duets to sexual uses, for other- 

 V7ise self-impregnation would usually occur. 



Certain recent researches seem to favour the view of the probable 

 origin of hermaphroditism from the conversion of the parts of the sexual 

 cells of one sex to sexual elements of the other. Many points of great 

 interest are concerned in Spengel's critique ^ of two papers , one by 

 BouRNE^, the other by Marshall 3, and in an earlier work of Spen- 

 gel's 4. Spengel in this review declares bis conviction that the so- 

 called Bidder's organ of the Amphibia cannot be regarded as the rudi- 

 ment of a female sexual organ , whatever else it may be , for it is pre- 

 sent in both sexes, and that wben a real hermaphroditism oc- 

 curs among Amphibia Bidder's organ is not concerned in 

 its formation, but that such hermaphroditism is brought 

 about by the transformation (Umwandlung) to ovary of 

 part of the tissue which in a normal individuai forms 

 testes, and that in this ovary so produced the ova attain 

 their normal siz e and pigment. 



BouRNE describes a specimen of E. temjjoraria, which on the 

 right side possesses a well developed ovary, while on the left the an- 

 terior end of the ovary encloses an irregulär testis not sharply marked 

 off from the ovarial tissue. 



Marshall describes an individuai [B] which macroscopically 



1 Spengel, Zwitterbildungen bei Amphibien. Biol. Centralblatt. Bd. IV. 

 Nr. 8. p. 235—241. 



2 A. G. BouRNE, On certain abnormalities in the Common Frog. 1. Ihe oc- 

 currence of an ovotestis. Quart. Journ. Microsc. Sci. Voi. 24. p. 83—86. PI. IV. 



3 A. M. Marshall , On certain abnormal conditions of the reproductive or- 

 gans of the common frog. Journ. of Anat. and Physiol. Voi. 18. p. 121—144. 



PI. VI— VII. 



4 Spengel, Arbeiten aus dem Zool.-Zoot. Inst, zu Würzburg. Bd. III. 1876. 



