Imatges de pàgina
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and the southern parts of Africa in general present us with Sagra, Diopsis, and Paussus, although it may be observed that some of these also occur in the East Indies. The lastnamed genus is remarkable for the very peculiar form of the antennæ. The genus does not exist in the twelfth edition of the Systema Nature, but was published by Linnæus in a separate dissertation in 1775. Only a single species was known at that period, and another was added in 1796, by Dr. Adam Afzelius, then residing at Sierra Leone.* The etymology of the name is supposed by Afzelius to be from the Greek Tavous, signifying a pause, cessation, or rest; for Linnæus, now old and infirm, and sinking under the weight of age and labour, saw no probability of continuing any longer his career of glory. "He might, therefore," adds Dr. Shaw, "be supposed to say 'hìc meta laborum,' as it in reality proved, at least with regard to insects,-pausus being the last he ever described." It was literally, in the language of Young,—

"An awful pause prophetic of his end!"

Both Madagascar and St. Helena present a few insects which to a certain extent demonstrate the African complexion of those islands; but the latter especially is also allied by its entomological features to some of the southwestern countries of Asia. According to Latreille, Africa furnishes no species of the genus Passalus, although it is elsewhere widely distributed over America and the East Indies. The genera Graphyptera, Eurichora, and Pneumora are probably peculiar to Africa.

Among the hemipterous insects of Africa we may mention the Mantis precaria, an object of superstitious veneration among the Hottentots, who hold in the highest respect the person on whom the insect happens to alight.

"I here became acquainted," says Mr. Burchell, in his Travels in the Interior of Southern Africa, "with a new species of Mantis, whose presence became afterward sufficiently familiar to me, by its never failing, on calm warm evenings, to pay me a visit as I was writing my journal, and sometimes to interrupt my lucubrations by putting out

* Linn. Trans., vol. iv.

† General Zoology, vol. vi. p. 43

the lamp. All the mantis tribe are very remarkable insects; and this one, whose dusky sober colouring well suits the obscurity of night, is certainly so by the late hours it keeps. It often settled on my book, or on the press where I was writing, and remained still, as if considering some affair of importance, with an appearance of intelligence which had a wonderful effect in withholding my hand from doing it harm. Although hundreds have flown within my power, I never took more than five. I have given to this curious little creature the name of Mantis lucubrans; and having no doubt that he will introduce himself to every traveller who comes into this country in the months of November and December, I beg to recommend him as a harmless little companion, and entreat that kindness and mercy may be shown to him."*

Locusts are of common occurrence in many parts of Africa. Mr. Barrow records, that in the southern districts which he visited, the surface of an area of nearly 2000 square miles might literally be said to be covered by them. The water of a wide river was scarcely visible in consequence of the innumerable dead locusts that floated on its surface, apparently drowned in their attempts to reach the reeds which grew along its shores. Except these muchwished-for reeds, they had devoured every other green thing. Their destruction on a former occasion was sudden and singular. All the full-grown insects were driven into the sea by a tempestuous north-west wind, and were afterward cast upon the beach, where they formed a bank three or four feet high, and extending nearly fifty English miles. The smell, as may easily be supposed, was abominable, and was sensibly felt at a distance of 150 miles.

The migratory flight of the locust, and its desolating effects upon vegetation, and consequent injury both to man and beast, have afforded a frequent exercise to the pen of the poet; but by none have their injurious inroads been so magnificently treated as by the Prophet Joel. "A day of darkness and of gloominess, a day of clouds and of thick darkness, as the morning spread upon the mountains; a great people and a strong there hath not been ever the like, neither shall be any more after it, even to the years of

* Burchell's Travels, vol. i. p. 418

many generations. A fire devoureth before them, and behind them a flame burneth: the land is as the Garden of Eden before them, and behind them a desolate wilderness yea, and nothing shall escape them. The appearance of them is as the appearance of horses; and as horsemen, so shall they run. Like the noise of chariots on the tops of mountains shall they leap, like the noise of a flame of fire that devoureth the stubble, as a strong people set in battlearray." "The earth shall quake before them; the heavens shall tremble: the sun and moon shall be dark, and the stars shall withdraw their shining." "How do the beasts groan! the herds of cattle are perplexed, because they have no pasture; yea, the flocks of sheep are made desolate."

One of the most formidable of the insect tribes of this continent is the Termes bellicosus, or white ant. This species dwells in congregated troops, consisting of labourers, soldiers, and sovereigns. They build conical nests of mud and clay, from 10 to 12 feet high, and divided in the interi^ by thin partitions into a variety of cells. These nests ar often very numerous, and appear like villages from a distance. Jobson, in his History of Guinea, alleges that they are often 20 feet high, and he states that he found them extremely serviceable in screening himself and his companions while engaged in the pursuit of antelopes and other wild game. The queen-mother of this species becomes in the pregnant state of so enormous a size, that her abdomen exceeds by two thousand times the bulk of the rest of her body. When the ova are fully formed, they are obtruded at the rate of 60 in a minute, or upwards of 80,000 in 24 hours.

Of the butterfly tribe, of course, many beautiful species inhabit this far-spread continent; but as little is known of their habits and history, and we would seek in vain to express by words the splendid colours, the elegant and varied forms, and the exquisite pencilling by which they are adorned, we shall not here enumerate any of the African species;

"Nameless in dark oblivion they must dwell,"

except in the minds of those who have studied their gorgeous hues in the illumined pages of natural history, or in those far

more brilliant pages of the book of nature's self, where the most successful effort of art is transcended by a feeble insect's wing;-for the imagination of the poet and the painter cannot boast

"Amid their gay creation hues like these."

Several species of bee inhabit Africa. The banded bee (Apis fasciata) is an object of domestic cultivation; and in some parts of the country a particularly delicious honey is derived from the labours of this industrious insect. Wax is an object of considerable consequence in the commerce of Africa.

Scorpions and centipedes of enormous size and most forbidding aspect lurk beneath the stones, or glide with numerous feet over the sterile soil; and the poison of these creatures seems to exist in a stronger and more deadly state of concentration than in colder climes. Children frequently die from the bite of the scorpion in less than three days. In regard to the smaller domestic nuisances of the entomological class, we have few data from which to form an opi nion. We doubt not that dirt and indolence produce here as elsewhere their disgusting concomitants. Captain Lyon, however, observed, that although bugs were numerous, there were no fleas in Fezzan.

We come now to the last class of the animal kingdom, called Zoophytes. These, Professor Jameson has elsewhere remarked, "although the lowest in the scale of animated beings, are yet highly interesting in the sublime plan of creation. Their numbers exceed all calculation,the minuteness of many species is such that they are not to be discriminated by the aid of our most powerful microscopes, they form one extremity of the zoological scale of magnitude, of which the other is occupied by the gigantic whale of the Polar Regions. The coral-reefs, rocks, and islands of the tropical seas are formed by very minute zoophytes. These reefs, in some regions of the earth, have been traced for a thousand miles in length, forty or fifty miles in breadth, and to depths sometimes unfathomable, yet they are the work of the most minute animals in the creation. We find, too, whole beds of rocks, even en

ure hills, of very old formation, extending for hundreds of miles, characterized by the corals they contain, thus proving that these animals also existed in countless numbers in a former condition of our earth, and that then as at present, they assisted materially in adding to the solid matter of the globe. Zoophytes, from the simplicity of their structure, and the geognostic relations of the rocks in which they are occasionally found, appear to have been called into existence before the other classes of animals."*

The red coral (Corallium rubrum), of which are formed so many beautiful ornaments of female dress, and the value of which as an article of commerce is consequently great, occurs abundantly along the coasts of Tunis and the shores of the Red Sea. It is of comparatively slow growth, and is never found in such splendid masses as the madrepores. Light effects a powerful influence on its growth.

Thus, at a depth of from three to ten fathoms, it grows one foot in eight years; at the depth of from ten to fifteen fathoms, the same length in ten years; at the depth of one hundred fathoms, same length in twenty-five or thirty years; and at the depth of one hundred and fifty fathoms, the same length in forty years. It is also remarked, that in general the colour is deeper and richer in shallow than in very deep water. The coral of Barbary is not reckoned so fine as that of Italy or France."+

The common sponge (Spongia officinalis) forms also an article of traffic along some of the African shores.

We shall conclude our sketch of African zoology by a brief notice of a dangerous and disgusting animal (Filaria medinensis), commonly called the Guinea worm. This gigantic parasite contrives, in a way best know to itself, to enter beneath the skin of the human race, especially that of the legs, where it will remain for several years, attaining in the mean time to the enormous length of ten feet, and to the thickness of a pigeon's quill. According to the place and manner of its abode, it occasions pains more or less severe; and in the more unfortunate and disastrous instances, its continued presence is followed by convulsions and death.

* Murray's Historical Account of Discoveries and Travels in Africa. vol. ii. p. 471. + Ibid, p. 473

THE END.

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