FROGS AND TOADS 
131 
of a certain kind of tree, carries her eggs upon 
her back, and retains them in position within 
a kind of pouch formed by small folds of skin 
on either side of her body. 
In some Mexican frogs of the genus Nototrema , 
the females possess a pouch of a much more 
perfect nature, the skin gradually extending 
over the back during the breeding season 
until a completely closed chamber is formed. 
How the eggs are conveyed into this remark¬ 
able receptacle is not known, although it has 
been suggested that they are placed there by 
the male. 
Equally curious are the habits of the tree- 
frogs (Phyllomedusa) which wrap up their 
eggs between several leaves of a tree over¬ 
hanging a pond, fixing the edges together by 
means of a sticky secretion they produce, and 
leaving a small opening at the lower end of 
the nest through which the young ones fall 
when they hatch out, and drop into the 
water below. The female is stated to carry 
the male on her back while they proceed 
to fashion this curious domicile for their 
young. 
These frogs are also peculiar on account 
of the structure of their hands and feet, the 
innermost digits of which are opposable to 
the remainder, so that when the creatures 
