The Transformation of the Mexican Axolotl. 573 



ance with this, their mode of life had become com- 

 pletely modified ; they no longer lived in the water, 

 but remained concealed by day among the damp 

 moss of the vivarium, coming forth only by night 

 in search of food in dry places. 



I had been able to perceive the great difference 

 between the two stages of development from the 

 anatomical data with which I had long been 

 familiar, and which Dumeril had made known with 

 respect to the structure of his Amblystomas. But 

 the collecting of numerous details gives no very 

 vivid picture of the metamorphosis ; it was the 

 appearance of the living animal that first made me 

 conscious how deep-seated was the transformation 

 which we have here before us, and that this change 

 not merely affected those parts which would be 

 directly influenced by the change in the conditions 

 of life, such as the gills, but that most if not all 

 the parts of the animal underwent a transformation, 

 which could in part be well explained as morpho- 

 logical adaptation to new conditions of life, and 

 partly as a consequence of this adaptation (cor- 

 relative changes), but could not possibly be re- 

 garded as the sudden action of these changed 

 conditions. 



Such at least is my view of the case, according 

 to which a per saltum development of the species 

 of such a kind as must here have taken place, is 

 quite inconceivable. 



I may venture to assume that most observers 

 P p 2 



