6o6 The American Naturalist. [July, 
of the axolotl will need little additional description. The body- 
is catfish-shaped. A high membranous fin begins on the back 
just behind the head, and continues around the tail to the vent. 
Fore limbs with four fingers each, and hinder limbs with five toes 
each, are present. On each side of the head are three gills, of 
which the upper is the longest, and the lowest the shortest. The 
main stem of each gill bears on its lower edge a fringe of fila- 
ments in which the blood is brought into close contact with the 
water. The upper surfaces of the head and body are olive, mot- 
tled and speckled with black ; the whole lower surface is white. 
Reference has been made to the food of the tadpoles in their 
native haunts. Last season I obtained a large number of the 
young oi A. microstonmm and kept them for some time in a glass 
jar. Soon I found that their gills were disappearing, from which 
circumstance I concluded that they were transforming. Soon, 
however, it was also seen that some of them were also losing 
their legs ; whereupon I began to watch proceedings a little more 
closely. One was seen to seize another by a leg, and a struggle 
followed for the possession of the member. It was plain that they 
were devouring one another alive. Not knowing what else to do 
I procured some slender angle-worms, and breaking them in pieces 
threw them into the water. Soon a tadpole approched a section 
of the worm and began to show interest in it. Presently with 
a sudden leap he seized the morsel and shook it violently, as if 
he expected resistance. By sudden snaps and gulps the worm 
w^as soon worked down the tadpole's throat. A tadpole would 
in this way swallow a piece of worm of nearly his own diameter 
and an inch or more in length. After this my specimens were 
abundantly supplied with this diet, the cannibalism ceased, and 
the larvae increased rapidly in size. When they are not supplied 
with food they are able to endure hunger for a long period, but 
they do not grow. If one wishes to rear them in aquaria, one 
may easily strain out the Entomostraca of pond water, and thus 
furnish them with acceptable food. On the bottom of an aquar- 
ium in which a number of freshly-captured nearly-grown larvse 
had been kept for a few days, were found numbers of the shells 
of a small species of Planorbis or related genus of mollusks. 
