566 Studies in the Theory of Descent. 



Amblystoma in the neighbourhood of the lakes, 

 " nevertheless the larva (Axolotl) is so common 

 there that it is brought into the market by thou- 

 sands." De Saussure believes that in Mexico the 

 Axolotl does not undergo transformation. 2 The 

 same statement is distinctly made by Cope, 3 whose 

 specimens of Siredon Mexicanus bred in America, 

 even in captivity showed " no tendency to become 

 metamorphosed." On the other hand Tegetmeier 

 observed 4 that one out of five specimens obtained 

 from the Lake of Mexico underwent metamorphosis, 

 and this accordingly establishes the second fact, 

 viz. that the true Axolotl becomes transformed 

 under certain conditions into an Amblystoma when 

 in captivity. 



This last remark would be superfluous if, as was 

 for a long time believed, the Paris Axolotls, of 

 which the metamorphosis was first observed and 

 which at the time made such a sensation, were 

 actually Siredon Mexicanus, i.e. the Siredon which 

 alone in its native country bears the name of 

 Axolotl. In his first communication Dumeril was 

 himself of this opinion ; he then termed the animal 



\ 



* [Eng. ed. In 1878 Senor Jose M. Velasco published a 

 paper entitled " Descripcion, metamorfosis. y costumbres de 

 una especie nueva del genero Siredon" Memor. Sociedad 

 Mexicana de Historia Natural, December 26th. See Addendum 

 to this essay]. 



* Dana and Silliman's Amer. Journ., 3rd series, i. p. 89. 

 Annals Nat. Hist. vii. p. 246. 



1 Proc. Zoo. Soc. 1870, p. 1 60. 



