Literatur. 



Fecundation in the Tailed Batrachians. 



A suinmary Review of recent discoveries. 



By 



Cr. A. Boulenger, London. 



Extraordinary as it may appear, it is only witbin the last few 

 years that the mode of fecundation has been ascertained in our com- 

 mon Newts. To Gasco (11) is due the credit of the discovery. Ab- 

 andoning for his observations the use of ordinary aquaria, he devised 

 a means of watching the Newts from below, placing them in glass 

 vessels suspended to the ceiling of his laborator}'. GrAsco's first ob- 

 servations were made on Molge alpestris. The amorous games of the 

 Newts, so graphically represented by Rusconi (20), had been repeatedly 

 described since the last Century, and SpAiiLANZANi (25), as early as 1766, 

 had ascertained the impregnation to be internal. The current opinion 

 that the water serves as a vehicle to convey the spermatozoa to tha 

 female organs — a view which is still held by Chalande (7), had re- 

 ceived a severe blow on Siebold's (24) discovery of the receptaculum 

 seminis, but no satisfactory explanation was given of the manner in 

 which the spermatozoa reach these pouches. This mystery Gasco has 

 succeeded in elucidating in his masterly paper, which has since been 

 supplemented by his own investigations on the Axolotl (12), those of 

 Marie von Chauvin (10) on the transformed Axolotl, or Amblystoma, 

 and those of Zeller (29, 31) and E. 0. Jordan (14) on the European 

 and American Newts. 



We now know that the male Newts and Axolotls, after lengthy and 

 varied amorous preludes and evolutions around the female emit, at short 

 intervals and in front of her, several conical or bell-shaped spermato- 

 phores, adhering to the ground by their base and crowned by a spheri- 

 cal mass of spermatozoa, which she gathers with the lips of her cloaca, 

 whether by mere application or, as observed in the Axolotl, by her hol- 

 ding the spermatophore between her bind legs and pressing the mass of 

 spermatozoa into the cloaca. The spermatophores had been first de- 

 scribed by Robin (19) and Stieda (26). 



In most Newts, our British species in particular, and in the Axolotl, 

 the courtship is not accompanied by any sort of enlacement; all the 



