182 



ZOOLOG Y. 



ing of a different species, tliougli closely allied to that of 

 Colorado, Utah, and Wyoming. The Mexicans used the 

 animal as food. Late in the summer the siredons at Como 

 Lake, Wyoming, where we have observed tliem, transform 

 ill large numbers into the adult stage, leaving the water 

 and hiding under sticks, etc., on land. Still larger num- 

 bers remain in the lake, and breed there. Thousands of 

 the fully-grown siredons are washed ashore in the spring 

 when the ice melts. They do not appear at the surface of 

 the lake until the last of .June, and disappear out of sight 

 early in September. The eggs are laid in masses, and are 

 two millimetres in diameter. 



The change from the larva to the adult consists, as we 



Fig. 228.- Siredon or larval Salamander. From Tenney's Zoology. 



have observed, in the absorption of the gills, which disap- 

 pear in about four days; meanwhile the tail-fins begin to 

 be absorbed, the costal grooves become marked, the head 

 grows smaller, the eyes larger, more protuberant, and the 

 third day after the gills begin to be absorbed the creature 

 becomes dark, spotted, and very active and restless, leav- 

 ing the water. Their metamorphosis may be greatly re- 

 tarded and possibly wholly checked by keeping them in 

 deep water. 



Experiments made in Europe show that the legs and tail 

 of the axolotl, as of other larval saiamanders, maybe repro- 

 duced. On cutting off a leg of an axolotl the first of 

 November, it was fully re])roduced, tliougli of smaller size 

 than tlie others, a montli later. The tail, if partly re- 

 moved, will grow out again as perfect as ever, vertebras 



