312 



LOWER VERTEBRATES. 



as the City of Mexico. The species differ in the period at which they undergo their 

 metamorphosis. Most of the eastern species reach the adult state while yet of small 

 size, but the A. tenehrosum of Oregon becomes quite large before changing. The A. 

 tigrinum delays its metamorphosis for the longest period, and can be prevented from 

 completing it by continued submergence in the water. Another species, the A. mac- 

 ulatum of the Mexican lakes is not known to leave the larval state. Although it has 

 often been aiRrmed that this change takes place, on examination it has always turned 

 out that the species observed is the A. tigrinum. The A. maculatum is the axolotl 

 of the Mexicans, and is used by them as an article of food. It is probably edible 

 like the Protonopsis horrida, which I have fonnd to be excellent. 



Fig. m. — Ambhjsloma tigrinum, larva. 



The following notes on the Amblystoma tigrimtm refer lo a specimen from New 

 Jersey of about a foot in length, which I kept for some months in a fernery in my 

 study. It is nocturnal in its habits and remained during the day in its burrow. This 

 extended through the long diameter of its prison, and had three outlets which it 

 kept open. From one of them, as evening approached, it projected its head and 

 watched with attention what was going on in the room. The Amblystoma punctatum, 

 which I have also kept in confinement, has similar habits. When handled, it may 

 eject a stream of transparent fluid, like a toad. I made the following observation on 

 the habits of the A. tigrinum, at some ponds in Idaho Territory, twelve miles north of 

 the Market Lake. On the shore I found several specimens in various stages of transi- 

 tion from the larval condition. They mostly presented stumps of the branchial 



