Axolotl, the larval or tadpole form of salamanders of the genus Amblystoma, which ranges from Canada and Oregon to Mexico. The best known is the larva of Amblgstoma mexicanus, originally found in the lake which surrounds the city of Mexico, and, under the name Siredon pisciforme, made the type of a genus, which of course has now lapsed. When full grown the Axolotl is a stoutly built lizard-like animal, some nine or ten inches long, of a dark slate-colour, covered with black spots. The tail is flattened and has a semi-transparent membranous fin. the head is flat and broad, and carries three feathery gills on each side. In Mexico they are eaten by the natives and esteemed a delicacy. M. Dumeril, in 1865, was the first to demonstrate by actual experiment the larval character of this animal; and since then many observers have seen Axolotls develop into Amblystomes. They are frequently kept for this purpose in aquaria in this country, and may be bought of any dealer in aquarium requisites. The Rev. G. C. Bateman says : "The length of time which will elapse before the Axolotl becomes the perfect Amblystome will depend upon circumstances; sometimes it will lose its gills and develop into the air-breathing animal within twelve months, and sometimes it will remain an Axolotl for three or four years." The chief difference between the mature and immature form is that the gills and tail-fin of the latter are absorbed. Both forms lay eggs, some of which may develop into Axolotls and some into Amblystomes. The reason for this is not known, but probably depends upon environment.