The Transformation of the Mexican AxolotL 591 



(devoid of gills) can exist, as I have myself seen, for 

 many months, and probably also for a year in deep 

 water, although adapted for purely pulmonary 

 respiration ; whilst Axolotls, as I have already men- 

 tioned, can live well for a year in shallow water 

 poor in air. If their gills by this means become 

 shrivelled up or completely disappear, even this is 

 not adaptation in the Darwinian sense, but the 

 effect of directly acting external influences, and 

 chiefly of diminished use. 



A case entirely analagous to that of Filippi's 

 was observed by Jullien in 1869. Four female lar- 

 vae of Lissotriton Punctatus (Bell) (synonymous 

 with Triton Taniatus, Schnd.), taken from a pool, 

 proved to be sexually mature. They contained 

 mature eggs in their ovaria ready for laying, and 

 two of them actually deposited eggs. Four male 

 larvae found in the same pool, appeared to be 

 equally developed with respect to size, but their 

 testicles contained no free spermatozoa, but only 

 sperm-cells. 18 



I have met with a third case of a similar kind 

 mentioned by Leydig in his memoir, rich in in- 

 teresting details, "on the tailed Amphibians of 

 the Wurtemburg fauna." ! Schreibers, the former 

 director of the Vienna Museum, also found 

 " larvae " of Tritons with well- developed gills, but 

 of the size of the "adult male individuals," and, 



** Compt Rend. vol. Ixviii. pp. 938 and 939. 

 " Archiv f. Naturgcschichte, 1867. 



