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Rh of the adult population; thus, city children may very often be seen playing at being drunk, or at policemen and thieves, and at fighting. Nothing can be more pitiful than this compulsory perversion of a natural instinct into unwholesome ways. Among the best methods of recruiting city children, the author recommends the system of holiday "colonies," which is in vogue in several European countries. Selected, poor, weakly children, between the ages of seven and fourteen, are sent in colonies of from ten to forty each, under teachers, and the month constituting the school holiday is spent at farm-houses or school-houses in the open country. The improvement in health from these outings has been proved not to be temporary. Provisions for a similar purpose in some of the cities of the United States are commended. The laying out of cities needs to be modified with reference to the requirements of children. Wherever the element of space is involved in any proposed legislation, let the people support that which will give them the most space about their dwellings. They would save increased taxation in doctors' bills and burial expenses. They should remember that the most useful open spaces are those which are close to their houses. Distant parks are not substitutes for the occasional simple play-ground in the heart of the city. Both together form a provision for the young children as well as for the adults.

The Great Inland Depression of Brazil.—It is interesting, says Mr. J. W. Wells, in a paper on "The Physical Geography of Brazil," to note the great depression that extends through the center of the South American Continent, practically similar to what exists in the North American. A canoe can be navigated from the Rio Orinoco to the Rio Negro, thence to the Amazons, then up the Rios Madeira, Mamoré, Guaporé, and Alegré, where it will not be more than five or six hundred feet above the sea. It can then be hauled across a low, grassy flat, as is often done, to the Rio Agoapehy, and then descend by the Rio Jauru and Rio Paraguay to Buenos Ayres. The distance from the Amazons to the Plate by this route is about twenty-five hundred miles, of which sixteen hundred and fifty miles have already been traversed by steamers, leaving eight hundred and fifty miles to be navigated. But it must not be inferred that the whole of this route offers an almost uninterrupted course of navigable rivers; on the contrary, the remaining eight hundred and fifty miles that have not been explored by steamers, not only contain insurmountable obstacles to the passage of even the lightest-draught steamer, but in many places to even the ascent of a canoe. Yet this route will most probably be, in the more or less remote future, the main line of internal communication. By far the greater part of the lands of this natural way are as undeveloped as the Congo of Africa. A connection also exists between the Rio San Francisco and the Rio Tocantins. A canoe can leave the former river and go up the Rios Grande, Preto, and Sapão. The source of the last river is in a beautiful lake in a valley surrounded by fortress-looking table-topped hills; the margins of the lake are bordered by groves of grand Burity palms; on the west the lake drains out into a quick-flowing, considerable stream, the Rio Diego, joins a Rio Preto, and thence onward by the Rio do Sonno to the Tocantins. This journey could be made without once taking the canoe out of the water, except to descend with safety a few rough stretches on the western outlet of the lake.

The Gapes in Chickens.—Dr. H. D. Walker has contributed to the "Bulletin" of the Buffalo Society of Natural Sciences the result of the special investigations which he has made to determine the origin of the gape-worm (Syngamus trachealis) of fowls, lie believes it to be a parasite of the earth-worm (Lumbricus terrestris). Taking the opportunity of a prevalence of the gapes among the chickens, in 1883, and acting under the advice of Dr. Leidy, he sought for the Syngamus in the embryonic or larval condition, in some intermediate part. This might, he thought, be the earth-worm, the sow-bug (Oniscus asellus), or the garden-slug, all of which were found around the infected coops; while the coops that suffered most were near a bare spot of ground which was full of earth-worms. Parasites were found in the earth-worms and in the slugs. The three animals were fed separately to