182 
ZOOLOGY, 
ing of a dififcrent species, though 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 them, transform 
in 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. Tiie 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 salamanders, maybe repro- 
duced. On cutting off a leg of an axolotl the first of 
November, it was fully reproduced, though of smaller size 
than the others, a month later. The tail, if partly re- 
moved, will grow out again as perfect as ever, vertebrae 
