388 THE VIVARIUM. 
of his own, from the Lake of Mexico, undergo the metamorphosis 
just described, an account of which was published in the Pro- 
ceedings of the Zoological Society of London fcr 1870, p. 160. 
The attempt to obtain the transformation of Axolotls should 
be made while the Batrachians are young, say between six and 
twelve months of age, and before they have bred. 
A year or two ago I tried to bring about the transformation of 
some old Axolotls which had reproduced their species, and was 
only partially successful. JI placed the animals in a large 
aquarium containing some sand, gravel, an island gradually 
sloping into the water, which at its greatest depth was about 4in, 
The water was not removed daily by hand, but allowed simply to 
evaporate. In course of time the Axolotls lost much of their 
branchiz, most of the median fin, the appendages of their feet, 
and yellow spots slowly appeared on different parts of their body, 
but when they arrived at this condition they made no other 
progress in theirmetamorphosis. The water slowly evaporated 
until only a depth of about 3in. remained at the deepest part of 
the tank, and in this scanty quantity of water the creatures lived 
for something like a year. I did not venture to deprive them of 
all the water, lest they should die for want of it. <A little was 
occasionally added to make up for the loss through evaporation. 
Ultimately I replaced these partially-transformed Axolotls 
with the other Axolotls from whose company I had taken them. 
Their removal was made as an experiment, but unfortunately it 
was a fatal one. They died. Their death, however, I did not 
expect, for I was careful to see that they had access to an island 
which gradually sloped into the water. They, therefore, could 
choose water of any depth up to 6in. or 8in. to live in. Some- 
times I found them in the deepest water they could get to, and 
sometimes in the shallowest. 
The Axolotl is a native of the lakes near the city of Mexico. 
It is there so plentiful that it is frequently sold in the markets of 
Mexico, its flesh being highly esteemed by the natives of that 
country. I believe that it is only the lakes of Mexico which 
contain Axolotls, or larvee of the Amblystoma tigrinum, capable 
of reproducing their species while still in an immature condition. 
In other partsof America where this species occurs, the tadpoles 
