It appears reasonable to suppose that there will be witnessed in the United States a gradual shifting of live stock centers. During the past half century, the great central West has been noted for the production of live stock, particularly for beef, mutton and wool, as an incident of its pioneer development. Already the production of large herds of cattle and flocks of sheep has disappeared for the central West, and is now confined largely to Texas and the mountain states. The northeastern states are unrivaled in the production of grass, and have considerable areas less fitted for tillage than the prairie states. In time, therefore, the tendency will be for the regions best fitted to rear animals to increase their numbers of breeding animals. On the other hand, those states which produce grain in relatively large abundance may give more attention to fattening animals and to the production of dairy products which can be shipped long distances. As time advances, the history of other countries will doubtless be repeated. A greater distinction between the breeding and rearing of animals, and their fattening and preparation for market will occur. ADVANTAGES OF KEEPING LIVE STOCK Since animals occupy a place in practically all farm organizations, it is desirable to state briefly the advantages and disadvantages which may accrue to any individual enterprise. The most striking advantages affecting the farmer are: (1) Animals make it possible to use land that would otherwise be wholly or partly unproductive. Hillsides and mountain slopes, soil too stony to cultivate, fields traversed by winding streams, and land partially covered with trees, are familiar examples. As previously mentioned, only about one-half the farm area in this country is improved land, and only two-thirds, even of the improved land, is in cultivated crops. The other third of the improved land and a considerable portion of that half of the farm area known as unimproved land are utilized as pasture for domestic animals. (2) They make use of farm crops which would be entirely or partially wasted. Straw, the stalks of maize, clover and alfalfa hay and other leguminous forage crops would not have sufficient value to pay for raising if animals were not kept to convert them into useful products. In fact, the usefulness of a given animal may be judged by the economy with which he converts these otherwise useless products into food or other materials for the use of man. The most profound studies are being made to determine the conditions under which this takes place. (3) In thus acting as machines in manufacturing raw materials into finished products animals convert these coarse and bulky materials into those which are much more concentrated, thus making their transportation economically possible. A pound of beef has required food containing ten pounds of dry substance, and a pound of butter has required thirty pounds of dry matter to produce it.