it automatically, thus burying each in a little cell or niche, where
it undergoes its further development. The tadpoles pass through their
larval stage within the cell, and then hop out, in the four-legged
condition. As soon as they have gone off to shift for themselves, the
mother toad finds herself with a ragged and honeycombed skin, which
must be very uncomfortable. So she rubs the remnant of it off against
stones or the bark of trees, and re-develops a similar back afresh at
the next breeding season.

Almost never do we find a device in nature which occurs once only. The
unique hardly exists: nature is a great copyist. At least two animals
of wholly unlike kinds are all but sure to hit independently upon the
self-same mechanism. So it is not surprising to learn that a cat-fish
has invented an exactly similar mode of carrying its young to that
adopted by the Surinam toad: only, here it is on the under surface,
not the upper one, that the spawn is plastered. The eggs of this
cat-fish, whose scientific name is Aspredo, are pressed into the skin
below the body, and so borne about by the mother till they hatch. This
is the second instance of which I spoke above, where the female fish
herself assumes the care of her offspring, instead of leaving it
entirely to her excellent partner.

Higher up in the scale of life we get many instances which show
various stages in the same progressive development towards greater
care for the safety and education of the young. Among the larger
lizards, for example, a distinct advance may be traced between the
comparatively uncivilized American alligator and his near ally, the
much more cultivated African crocodile. On the banks of the
Mississippi, the alligator lays a hundred eggs or thereabouts, which
she deposits in a nest near the water's edge, and then covers them up