182 ANIMAL FORMS 
pearing as a smooth circular area behind the eye. Organs 
of touch, smell, and taste are likewise developed in varying 
degree of perfection. 
174. Breeding-habits—While the great majority of am- 
phibians mate in the spring and deposit their eggs in the 
water, often to the accompaniments of croakings and pip- 
ings almost deafening in intensity, several species, for 
various reasons, have adopted different methods. Some of 
the salamanders bring forth young alive, and several species 
of toads and frogs are known in which the young are cared 
for by the parent until their metamorphosis is complete. 
In one of the European toads (Alytes) the male winds 
the strings of eggs about his body until the tadpoles are 
Fig. 110.—Salamanders, The 
axolotl (the Jarva of Am- 
blystoma  tigrinum) and 2 — = ah 
the newt (Diemyctylus to- a SS 
: 1] 
7O8US), 
ready to hatch ; and in a few species of tree-toads the eggs 
are stored in a great pouch on the back of the parent until 
the early stages of growth are over. In the Surinam toad 
of South America the eggs are placed by the male on the 
back of the female, and each sinks into a cavity in the 
spongy skin. Here they pass through the tadpole stage 
without the usual attendant dangers, and emerge with the 
form of the adult. 
