A still more dangerous plague, peculiar to the coast of Guinea and the interior of tropical Africa, to Arabia, and the adjacent countries, is the _Filaria medinensis_ of Linnæus. This dreaded worm comes to the herbage in the morning dew, from whence it pierces the skin, and enters the feet of such as walk without shoes, causing the most painful irritation, succeeded by violent inflammation and fever. The natives extract it with the greatest caution by twisting a piece of silk round one extremity of the body and withdrawing it very gently. When we consider that this insidious worm is frequently twelve feet long, although not thicker than a horse-hair, we can readily imagine the difficulty of the operation. If unfortunately the animal should break, the part remaining under the skin grows with redoubled vigour, and frequently occasions a fatal inflammation. One of these most unwelcome intruders once entered Dampier’s ankle. ‘I was in great torment,’ says this entertaining traveller, ‘before it came out. My leg and ankle swelled, and looked very angry, and I kept on a plaster to bring it to a head. At last, drawing off my plaster, out came three inches of the worm, and my pain abated. Till that time I was ignorant of my malady, and a gentleman at whose house I was took it for a nerve; but I knew well what it was, and presently rolled it up on a small stick. After this I opened the place every morning and evening, and strained the worm out gently, about two inches at a time--not without some pain--till I had at length got it out.’ Among the plagues of Guiana and the West Indies we must not forget a little insect in the grass and on the shrubs, which the French call bête-rouge. It is of a beautiful scarlet colour, and so minute that you must bring your eye close to it before you can perceive it. It abounds most in the rainy season. Its bite causes an intolerable itching, which, according to Richard Schomburgk, who writes from personal experience, drives by day the perspiration of anguish from every pore, and at night makes one’s hammock resemble the gridiron on which Saint Lawrence was roasted. The best way to get rid of the plague is to rub the part affected with lemon-juice or rum. ‘You must be careful not to scratch it,’ says Waterton. ‘If you do so and break the skin, you expose yourself to a sore. The first year I was in Guiana the bête-rouge and my own want of knowledge, and, I may add, the little attention I paid to it, created an ulcer above the ankle which annoyed me for six months, and if I hobbled out into the grass, a number of bête-rouges would settle on the edges of the sore and increase the inflammation.’