bed of the ocean, my itinerant
tropical acquaintance (his name, I regret to say, is Callichthys) uses
them boldly for terrestrial locomotion across the dry lowlands of his
native country. And while the gurnard has no less than six of these
pro-legs, the American land fish has only a single pair with which to
accomplish his arduous journeys. If this be considered as a point of
inferiority in the armour-plated American species, we must remember that
while beetles and grasshoppers have as many as six legs apiece, man, the
head and crown of things, is content to scramble through life
ungracefully with no more than two.

There are a great many tropical American pond-fish which share these
adventurous gipsy habits of the pretty little Callichthys. Though they
belong to two distinct groups, otherwise unconnected, the circumstances
of the country they inhabit have induced in both families this queer
fashion of waddling out courageously on dry land, and going on voyages
of exploration in search of fresh ponds and shallows new, somewhere in
the neighbourhood of their late residence. One kind in particular, the
Brazilian Doras, takes land journeys of such surprising length, that he
often spends several nights on the way, and the Indians who meet the
wandering bands during their migrations fill several baskets full of the
prey thus dropped upon them, as it were, from the kindly clouds.

Both Doras and Callichthys, too, are well provided with means of defence
against the enemies they may chance to meet during their terrestrial
excursions; for in both kinds there are the same bony shields along the
sides, securing the little travellers, as far as possible, from attack
on the part of hungry piscivorous animals. Doras further utilises its
powers of living out of water by going ashore to fetch dry leaves, with
which it builds itself a regular nest, like a bird's, at the beginning
of the rainy season. In this nest the affectionate parents carefully
cover up their eggs, the hope of the race, and watch over them with the
utmost attention. Many other fish build nests in the water, of
materials naturally found at the bottom; but Doras, I believe, is the
only one that builds them on the beach, of materials sought for on the
dry land.

Such amphibious habits on the part of certain tropical fish are easy
enough to explain by the fashionable clue of 'adaptation to
environment.' Ponds are always very likely to dry up, and so the animals
that f