318 LEISURE-TIME STUDIES. 



newts, which, like other amphibia, possess gills in early life, 

 but breathe when adults by lungs alone. This transformation 

 of the axolotl into a completely different animal, with which 

 it was not known to possess any relationship whatever, 

 excited, as might be supposed, no small amount of interest, 

 especially when the presumably adult nature of the axolotls 

 was kept in view. Professor Marsh, of New Haven, U.S., 

 has placed on record the fact, that a species of axolotl 



FIG. 64. Amblystoma, a North American newt. 



{Siredon lichenoides) common in the western parts of the 

 United States, also loses its gills and fins when kept in con- 

 finement, and exhibits other changes of structural nature. 

 This species further assumes the likeness of a species of am- 

 blystoma (A. mawrtiuni) ; and Professor Marsh has also 

 remarked that the changes just described occur when these 

 axolotls are brought from their native lakes situated in the 

 Rocky Mountains at an altitude of 4500 to 7000 feet to 

 the sea-level. 



The exact causes of these curious changes have only 

 recently, and through the perseverance and ingenuity of 

 a lady experimenter, Fraulein Marie von Chauvin, been 

 brought to light. This lady's experiments confirm in a very 

 striking manner the ideas biologists have been led to form 



