must confine ourselves to a brief allusion to a very limited number of the African tribes.

1st, Chelonian reptiles, or tortoises and turtles. Several of this division occur in Africa, such as the Testudo Græca, the Testudo triunguis, &c.

2d, Saurian reptiles. To this division belong the crocodiles and lizards, the geckos, chameleons, and many others.

The common crocodile (Lacerta crocodilus), celebrated in the ancient history of Egypt, is spread over a considerable extent of this continent.

"'Ere while, emerging from the brooding sand,
With tiger paw he prints the brineless strand;
High on the flood, with speckled bosom swims,
Helmed with brood tail, and oared with giant limbs ;
Rolls his fierce eye-balls, clasps his iron claws,
And champs with gnashing teeth his massy jaws.
Old Nilus sighs thro' all his cane-crowned shores,
And swarthy Memphis trembles and adores."

There are several different kinds of crocodile in the old and new world, and their tempers and dispositions seem to vary in different localities. Hum boldt and Mungo Park regarded them with fear and trembling, whilst Audubon and Mr Waterton hold them in little consideration either as friends or foes. Though seldom tamed, they are not by any means incapable of domestication, as has been demonstrated by many examples, both in ancient and modern times.

Many lizards occur in Africa. We shall only mention one found near Mourzouk. It is called aselis, and, if not a true lizard, resembles one in form. When alarmed, it buries itself in the sand; and, when dropped from a height, it immediately sinks beneath the surface of the spot on which it fell. "These little creatures," says Captain Lyon,

"are eagerly bought by the girls and married women, for the purpose of ascertaining how many children they shall have. By stretching them the skin will immediately crack, and the women most religiously believe that for every sound they shall bear a child."

One of the most remarkable families of the saurian tribe is that which contains the chameleons. The common species (Lacerta Africana) is found in Egypt, Barbary, and the South of Spain. The changes of colour in these animals, though by some deemed fabulous, are now beyond dispute. The causes of these changes, however, and their mode of action, may still be classed among the more obscure points of natural history. They seem independent of external objects, and vary within a certain range, almost every hour.

"Non mihi tot cultus numero comprendere fas est: Adjicit ornatus proxima quæque dies."

3d, Ophidian reptiles, or serpents. Among the most remarkable of the African species of this division, is the cerastes, or horned viper. It is characterised by a small curved horn over each eye-lid. It lives in the sand, and was well known to the ancients. Another singular serpent is the haje (Coluber haje, Linn.). The Egyptian jugglers, by pressing the neck of this creature between their fingers, produce a kind of catalepsy which renders it stiff and motionless. This is rather a curious fact when considered in connexion with the scriptural narrative in the seventh chapter of Exodus, where the rods of the magicians when thrown down are converted into serpents.

This species was regarded by the ancient Egyp

tians as the emblem of the protecting divinity of the world, and its figure is frequently sculptured on each side of a globe, on the outer gates of their temples.

4th, The Batrachian reptiles, such as frogs, &c. Africa produces comparatively few species of this division. The soil is probably too dry. We shall here mention only the short-headed toad (Rana breviceps) described by Linnæus in the Amanitates Academica, vol. i. It is a very small species, native to Senegal and some other parts of Africa.

The great and almost inexhaustible class of fishes next demands our attention.

Our acquaintance with the laws which regulate the geographical distribution of this class is extremely meagre in other words, the facts illustrating the greater or less extension of their localities are few, and have never been properly generalized. From the immeasurable extent and continuous nature of the fluid which they inhabit, they are supplied by nature with greater facilities of dispersion than most other animals; while the greater equality of the temperature of water, when compared with that of either earth or air, admits, in several instances, of the same species inhabiting almost every latitude from pole to pole. Those races especially, which, travelling together in vast shoals, speedily consume the natural food which each particular spot affords, are obliged like the pastoral tribes of old, or the woodland hunters of America, to remove from place to place in search of additional supplies, and thus the species acquires a more widely-extended geographical distribution. It is thus that the cod and herring are spread over the whole extent of the Northern

Ocean, and in undiminished numbers, notwithstandstanding the war of extermination which man and other voracious animals appear to wage against them. Those species which lead a solitary, and as it may be called, a stationary life, are frequently confined within very narrow limits. The Chatodons, for example, which delight in rocky coasts covered with madrepores, attach themselves to the torrid zone, which produces so abundantly those magnificent ornaments of the sea. But though thus confined to particular spots, from which the individuals of the species never wander, the species itself may be said to be repeated again in different and distant regions, separated from each other by almost insurmountable obstacles. Thus many of what may be termed stationary species are found identically the same along the coasts of Brazil, in the Arabian Gulf, and over the multiplied shores of Polynesia. It has hence been concluded that such species, incapable of colonizing themselves by leaving their accustomed shores, and hazarding a journey across unknown oceans, have either been created in more places than one, or have been enabled to transport themselves by means different from any of those which are now available in the ordinary course of nature.*

If the natural means by which the more powerful species, inhabiting the saline waters of the ocean, have spread themselves from clime to clime, be in some measure within the reach of our comprehension, it is otherwise with those peculiar to rivers and the waters of inland lakes. How these have

* See Gaymard's Mémoire sur la Distribution Géographique

des Poissons.

contrived to migrate from one region to another, and to people with identical species the depths of farremoved and solitary waters, separated from each other by chains of lofty mountains, or wide-extended wastes of desert sand, is a problem which, in the present state of our knowledge, we seek in vain to solve.*

Of the genus Muræna several species occur in the African seas. The spotted muræna (M. guttata) was observed by Forskall in the Red Sea. A small species of goby, scarcely exceeding an inch in length, is found in the Nile. It is the Gobius aphya of Linn. We may here mention that the name aphya, by which this species has been distinguished, seems to have been applied by the ancient writers to such small fishes as they vaguely supposed to have been produced rather from the foam of the ocean than according to the usual process of nature. Several species of bull-head (Cottus) are described by Commerson, and the genus Scorpaena, so eccentric in its forms, is represented in the African seas, among others by the Cape scorpæna (S. Capensis), mentioned by Gronovius. A magnificent fish called the opah dory (Zeus luna), inhabits the African shores. Dr Mortimer exhibited a fish of this kind to the Royal Society in 1750, which was taken "on the coast of Leith ;" and he adds (in the Phil. Trans. for that year) that the Prince of Anamaboe, being then in England, immediately recognised it, and said it was common in his country, and was excellent eating.

The Remora, so remarkable for its faculty of ad

* See further on this subject the 5th number of my Illustrations of Zoology.

+ See Shaw's General Zoology, vol. v. p. 245.