The distance that the malarial mosquito can fly is of interest as indicating the distance which one must go from a house, hunting for available pools. All mosquitoes are unable to fly against the wind, so that, as already noted, one side of a swamp may be comparatively free from malaria, while the other side may be overrun with it, merely on account of the direction of the prevailing winds. Some mosquitoes that breed in salt marshes may be carried for miles, so that a land breeze will bring millions of the pests to seashore cottages which, with a sea breeze, are quite free from them. The anopheles has a habit of clinging to weeds, shrubs, and bushes when the wind blows, so that it is seldom carried more than about two hundred yards from the place where it is hatched. If all pools of water, therefore, within this radius are disposed of, the elimination of malaria will logically follow. If one is obliged to be in a region where malaria is common, the disease can be avoided absolutely by protecting one's self from mosquitoes, and since the anopheles prefer the early morning and evening hours, it is at those times of the day particularly when precautions must be taken. It was once thought that the night air caused malaria, and this had some foundation in fact, because it is in the early evening that the anopheles is on the wing. By staying in the house after sundown and by carefully screening the doors and windows, one may live in a malarial country with perfect immunity. Volunteers have lived for months in the worst malarial regions in the world without a trace of the disease, the only precaution being to keep the doors and windows screened and to prevent mosquitoes from biting. An interesting experiment was made some years ago by sending a malarial mosquito by mail from Italy to England, where an enthusiast allowed himself to be bitten by the insect. He had had no trace of malaria before, but a week after the mosquito's bite he came down with the disease. It has also been noted that in such parts of the country as Greenland and Alaska, where mosquitoes are as thick as in the far-famed New Jersey marshes, malaria does not result from the mosquito bites unless a malaria patient from other countries starts the infection.