346 INEZ WHIPPLE WILDER AND ELIZABETH BARRETT PEABODY. 



had examined for the possible occurrence of a Bidder's organ, an 

 enumeration which included seven species of Anura and two of 

 Urodcla (Triton tfcniatus and Salamandra metadata) Knappe 

 states definitely " Bald stellte sich heraus, dass es zur Bildung 

 eines Bidder'schen Organs nur bei den echten Krotenarten 

 kommt." And farther on after mentioning the unique appearance 

 of one Bidder's organ, he says: 'Eine solche Samenkorperbil- 

 dting in Eikapseln des Bidder'schen Organs mit gleiches Be- 

 stimmtheit nachzuweisen, wie in dem eben beschriebenen Falle, ist 

 mir bis jetzt nicht wieder gelungen, doch kann ich ahnliches fur 

 eine andere verwandte Thiergruppe, die Salamander, konstatiren. 

 So liess eine in Schnittserien zerlegte Hodenabtheilung eines 

 jungen, viellicht zweijahrigen Salamandra maculata nicht den 

 geringsten Zweifel, dass dieselbe aus Eikapseln, ahnlich denen im 

 Bidder'schen Organ der Kroten, bestaht." It was thus obviously 

 not Knappe's intention to state that he found a Bidder's organ 

 in a salamander, but rather an appearance in the testis of a 

 salamander like that of the unique Bidder's organ in a toad. In 

 any case the interpretation of the condition described in the sala- 

 mander as hermaphroditic, will depend upon the interpretation 

 of the sexual nature of Bidder's organ itself. This is a matter 

 which has been a bone of contention ever since the discovery of 

 the organ in 1758 by Rosel von Rosenhof, and a number of the- 

 ories have been advanced regarding its nature and significance. 



In view of the almost universal agreement of modern writers 

 as to the femaleness of Bidder's organ, Swingle's recent discussion 

 ('21 and '22) of its nature is of great importance. In a discus- 

 sion of the so-called transformation of sex in frogs, he claims that 

 the theory is really based on a misinterpretation of the appearance 

 of the cells in the Bidder's organ of toads. According to Swingle, 

 the ovi form-like cells of this organ do not represent the cells of an 

 ovary, thus making the animal an hermaphrodite at this stage, 

 but are, like the cells of similar appearance which occur in the pro- 

 testis of the frogs, merely senescent male cells which are under- 

 going oviform degeneration. He adds further : " True hermaphro- 

 ditism in frogs is a permanent and pathological condition, prob- 

 ably due to a mix-up in the genetic constitution of the individual. 



