In hunting the gymnoti the Indians adopt a cruel expedient. They drive a herd of horses and mules into the ponds which these eels inhabit, and harpoon them when they have spent their electrical force on the unhappy quadrupeds. The fish swim on the surface of the water like serpents, and skilfully glide beneath the animal's body, discharging the whole length of their electrical battery, and attacking simultaneously the digestive viscera, and, above all, the gastric plexus of nerves. Fain would the horses escape their enemies' attacks, but the Indians drive them back into the water with stout canes of bamboo and long whips. After awhile the eels grow exhausted; the animals show less alarm; and the Indians begin to ply their harpoons with equal agility and success. There are several species of this remarkable fish, and most, if not all, are valued as wholesome food. The Gymnotus Electricus, however, is the only one which possesses any electrical powers. CHAPTER XII. ANIMAL LIFE IN THE AUSTRALIAN PRAIRIES. The first naturalists who explored the littoral of the Australian continent and its adjacent islands were struck with astonishment at the sight of the strange and almost monstrous animals they discovered there. Far more certainly than Columbus had they fallen in with a New World; a new world of zoology and botany; a world apart, peopled by beings wholly different from those they had elsewhere studied, and some of which exhibited a complexity and originality of organization and structure wholly antagonistic to the received theories of fundamental characteristics belonging to the various classes of the animal kingdom. The Australian Fauna, in this respect, can only be compared to that of Madagascar, which equally bears an impress peculiarly its own, and presents but a few features of kinship with the Indian Fauna. It is the latter also that the Australian Fauna most closely approaches, or, to speak more correctly, from which it least widely diverges. The great Herbivora--Pachyderms, Ruminants, and Solidungulates--are absolutely wanting in Australia, as well as the Carnivora properly so called--Apes and Lemuridæ. The class of Mammals is only represented by a small number of Cheiroptera and Rodents; by some Amphibia, Phocæ, and Otidæ (Seals and Bustards), which inhabit the bays carved out of its long line of coast; by the Marsupials and a very limited order of Monotremata. The two latter groups are pre-eminently characteristic of the Australian Fauna; the second belongs exclusively to it. Little, indeed, is wanting to make it identical with the sub-class of the Marsupials, represented only in South America by the genera Opossum didelphis, Hemiurus, and Chironectes, and elsewhere limited to New Holland, Tasmania, New Guinea, New Zealand, and some other less important islands of Oceania.