CHAPTER XXII.

Natural History of the Reptiles, Fishes, Shells, Insects, &c. of Africa.

Introductory Observations-Crocodiles-Lizards-Chameleon Serpents -Frogs-General Observations on Fishes-Muræna-Gobius-CottusScorpæna-Zeus-Remora-Labrus-Mackerel-Surmullet - Flying Gurnard-Electric Silure-Salmon-Polypterus-Argentine-Flyingfish-Polyneme-African Herring-Carp-Mormyrus-Ray- Ostracion -Tetrodon-Pipe-fish-Fossil Fish-General Observations on ShellsVarious African Species-Remarks on the Distribution of InsectsGoliathus, &c.-Paussus-Mantis-Locusts-Butterfly Tribe-BeesScorpions-Centipedes-Zoophytes-Coral Sponge-Guinea Worm. INTERMEDIATE between the birds and fishes are the reptile race, divided by naturalists into four principal branches, the Chelonian, the Saurian, the Ophidian, and the Batrachian reptiles. Of all these Africa, " fruitful in monsters," produces some remarkable examples.

In regard to the geographical distribution of reptiles, the first and most general observation is, that they augment in number as we advance towards the equatorial regions. While Sweden possesses scarcely a dozen lizards and snakes, about three or four frogs and toads, and not a single tortoise, the temperate parts of Europe produce about forty snakes and lizards, and several of the tortoise tribe. As soon as we reach the southern extremity of Spain, the number of species in these tribes greatly increases, and in Andalusia the African complexion of the country is still farther manifested by the appearance of the chameleon. On proceeding farther south, not only does the number of reptiles increase, but they also augment in size, till, from the Tropic of Cancer, onwards, and beyond the Line, we meet with crocodiles, caymans, boas, and other giants of that race. For the present, however, we must satisfy ourselves with 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 that continent, 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.

"Erewhile, emerging from the brooding sand,
With tiger paw he prints the brineless strand;
High on the flood, with speckled bosom swims,
Helm'd with broad tail, and oar'd with giant limbs;
Rolls his fierce eyeballs, clasps his iron claws,
And champs with gnashing teeth his massy jaws.
Old Nilus sighs through all his cane-crowned shores,
And swarthy Memphis trembles and adores."

There are several different kinds to be found in the old and new world, and their tempers and dispositions seem to vary in different localities. Humboldt and Mungo Park regarded them with great fear, 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; but we shall only mention one found near Mourzouk, called aselis, which, if it be not a true lizard, certainly resembles them 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, by some deemed fabulous, are now beyond dispute, though the cause of these variations must 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 characterized by a small curved horn over each eyelid; 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 it is related

*For the general history and systematic arrangement of these and other reptiles, consult the articles Reptilia and Serpents in the seventh edition of the Encyclopædia Britannica.

that the rods of the magicians, when thrown down, were converted into serpents.

This species was regarded by the ancient Egyptians 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. Of this division, containing such as frogs, &c., Africa produces comparatively few species. The soil is probably too dry. We shall here mention only the short-headed toad (Rana breviceps) described by Linnæus in the Amanitates Academicæ, vol. i. It is a very small species, a native of Senegal and some other parts.

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 larger 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 that 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 in this way the species acquire 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, notwithstanding 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 any 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 ones 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 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 contrived to migrate from one region to another, and to people with identical species the depths of far-removed and solitary waters, separated from each other by chains of lofty mountains, or widely-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 Murena several species occur in the African seas. The spotted muræna (M. guttata) was observed by Forskall in the Red Sea; and a small species of goby, scarcely exceeding an inch in length (the Gobius aphya of Linn.), is found in the Nile. 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 Scorpena, so eccentric in its forms, is represented in the African seas, among others by the Cape scorpæna (S. Capensis), mentioned by Gronovius; and a magnificent fish called the opah dory (Zeus luna) inhabits the same shores. Dr Mortimer exhibited a specimen 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 adhering to other fishes by a peculiar sucker-shaped organ on the top of its head, is found in the Mediterranean and other saline waters which wash the African borders. The olive-green remora (Echeneis cauda rotundata of Bloch) is common on the coasts of Mozambique. A species of Labrus (L. Niloticus) inhabits the Nile; and the star-eyed Bodian (Bodianus stellifer) is a native of the seas about the Cape. The silvery mackerel (Scomber crumenophthalmus), is found in considerable plenty on the coasts of Guinea, and the Scomber chloris is also regarded as an African species.

The surmullet (Mullus ruber) so famous as an epicurean delicacy among the Romans, and so highly, though not very humanely admired for the splendour of its dying hues, is found both along the African and European shores of the Mediterra"Vide," says Seneca, " quomodo exarserit rubor omni

nean.

*See Gaymard's Mémoire sur la Distribution Géographique des Poissons. See farther on this subject the 5th number of Wilson's Illustrations of Zoology.

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

acrior minio! vide quas per latera venas agat! Ecce! sanguinem putes ventrem! quàm lucidum quiddam cœruleumque sub ipso tempore effulsit! jam porrigitur et pallet, et in unum colorem componitur!" The flying gurnard (Trigla volitans) may likewise be mentioned as a Mediterranean species of singular habits and great beauty. It swims in shoals, and delights the voyager by its short and frequent flights.

The electric silure (Silurus electricus) dwells in the rivers of Africa. It was observed by Forskall in the Nile, by whom, however, in his Fauna Arabica, it is improperly named Raja torpedo. Another species of Silurus called platte-kop, or flathead, occurs in the fresh waters of Southern Africa. Mr Burchell observed two boys of the Bushmen tribe fishing for this species, who stood by the water-side, motionless as herons. After waiting patiently for half an hour, a fish came within their reach, and was instantly pierced through with their spears or assagays. It was nearly three feet long, entirely of a lead colour, but approaching to white underneath. The head was very broad and flat, the eyes pale yellow, and extremely small, and the mouth was bearded with several very long strings. The flesh was white, rich, and nutritious. It seems to occur only in those rivers which run to the western coast (that is, to the northward of the Cape of Good Hope), while, on the other hand, eels have never been seen in any but those which fall into the ocean eastward of that promontory.

Of the salmon genus, the Salmo fulvus, a fierce and hungry fish, is much esteemed as an article of food by the inhabitants of Guinea. The notable genus Polypterus was first scientifically distinguished by M. Geoffroy. Its shape is long, cylindrical, and serpentiform; the head is defended by large bony plates; and the body is covered by strong scales, resembling those of a coat of mail. This fish is called bichir by the Egyptians, and is considered as very rare. It is said to dwell in the soft mud of the Nile, and is the finest flavoured of all the Nilotic varieties; but as it is hardly possible to open the skin with a knife, the fish is first boiled, and the integument afterwards drawn off almost entire. The tooth-tongued argentine (A. glossodonta) is a beautiful species, a native of the Red Sea; and the pearl-bladdered argentine (A.Sphyraena) is a Mediterranean fish of the same genus. The air-bladder which distinguishes it, is equally bright and beautiful with its external parts, and along with these, is much used in the preparation of artificial pearls. The flying fish (Exocatus exiliens) is remarkable for the great length of its pectoral fins, which enable it to sustain itself above the waves for several hundred yards. The silvery polyneme (P. Niloticus) is a very elegant fish, of great excellence as an article of food, and its mode of capture in the Nile is described by Bruce. The ten-fingered polyneme (P. decadactylus), likewise esteemed very wholesome and agreeable, occurs along the coasts of Guinea, and occasionally enters the rivers of that country. Of species allied to the herring, Africa produces several varieties. The Clupea Africana is said to be extremely