TREE-FROGS. 343 
species of all its family. It soon becomes so tame as to take 
food from its owner’s fingers. By the help of the disks with 
which the extremities of the fingers and toes are furnished it is 
able to cling for hours to the glass sides of its Vivarium. 
The Green Frog becomes particularly lively towards evening, 
sometimes making so loud a croaking that it may be heard a 
very long distance. Lord Clermont says that when “ there are 
many together, they may be heard for two miles or more around.” 
The “ Royal Natural History” remarks that ‘‘ when croaking, 
- the sac on the throat of the males becomes so inflated as to make 
this appendage nearly as large as the body.” 
The European Tree-frog, owing to the colouring of its body, is 
very difficult to distinguish when at rest upon some green leaf. 
For this reason it is called in Germany Laubfrosch, or Leaf Frog. 
Flies and other insects, therefore, often come into the close 
neighbourhood of their enemy without any suspicion of danger. 
The Batrachian’s active tongue shoots out and is as rapidly 
withdrawn, and the victims disappear, perhaps without having 
had time to experience any fear or pain. 
This Tree-frog is very fond of flies and earwigs; but it will eat, 
besides these creatures, mealworms, cockroaches, earthworms, 
and the like. It jumps upon its prey from the distance of a foot, 
or even more. Like some other Batrachians, it can be tempted 
to take pieces of meat. when moved before it at the end of a wire. 
H. arborea spawns from April to June, and for this purpose it 
leaves the trees where it chiefly dwells and takes to the water. 
It will spawn in captivity if it be placed in a Vivarium which 
possesses a large tank, well sheltered by growing plants. During 
the breeding season the water should not be changed if the Frogs 
are wished to deposit spawn. When the eggs have been extruded 
they should be carefully removed from the tank and placed, as 
already suggested, in some other vessel—a shallow one—con- 
taining soft water of the same temperature as that from which 
they have been taken. 
During the winter these Frogs should be allowed to retire 
under some damp moss or pieces of cork bark. When the 
weather is unusually mild and bright, for that season, they 
will sometimes leave their hiding-places and take cockroaches, 
