346 MOSTLY MAMMALS 
them to her consort. Whereas there is nothing remarkable 
about the structure of the female of this frog, the male 
has a capacious pouch underlying the whole of the lower 
surface of the body, which communicates with the exterior 
by means of a pair of apertures opening into the mouth 
on each side of the tongue. As soon as his partner has 
deposited her eggs, the male frog takes them in his front 
paws and transfers them to his mouth, whence they pass 
into the great nursing-pouch, where they remain in perfect 
security till hatched into young frogs, which make their 
way into the world by the same passage. 
Peculiar as is this method of taking care of the eggs, it 
is by no means altogether without a parallel in the animal 
kingdom, although we have to go to the class of fishes to 
find anything approaching a similar example. Among the 
so-called cat-fishes (Si/uridae), the males of several species 
of the large tropical genus Avzus take the eggs into their 
mouth, whence they are transferred to the capacious 
pharynx, where they remain until hatched. It is also said 
that among the fresh-water fishes of the chromid family, 
the males of the typical genus inhabiting the Sea of 
Galilee take charge of the eggs in a similar manner. 
Indeed, among the comparatively few fishes that take any 
care at all of their ova, the charge almost invariably falls 
to the share of the long-suffering male, whose partner, 
having laid the eggs, appears to think that she has done 
quite enough in family matters, and is at full liberty to 
enjoy herself as she pleases. 
Of the two definitely known instances in which female 
fish take care of their eggs, one occurs among the aforesaid 
family of the cat-fishes, in the genus Aspredo, represented 
by some half-dozen species from the Guianas. In these 
fish, none of which exceed a foot and a half in length, the 
