Climate does not play so important a part in the United States in modifying animals and in producing variations as formerly, when stables were inferior and when it was sometimes the practice to allow horses and other domestic animals to find shelter around the straw-stack. As the forests were cleared, it was not uncommon to provide an open shed, usually facing the south or east, in which horses, cattle and sheep were allowed to battle for the place least exposed to drafts of air. Even if enclosed stables were built, the floor and sides were so open that the heat generated by the animals kept in them made no perceptible change in the temperature. Many of these stables were more uncomfortable for the animals than open sheds, or the barnyard, if it chanced to be somewhat protected from the winds.
Under such conditions, climate played an important part in modifying the growth and structure of both horses and cattle. But little improvement could be made in animals where they were subjected for nearly half a year to climatic conditions as damp and rigorous as those found in the greater part of the eastern and middle states. The improvement in horses which has been made in the last half-century could not have taken place had not the rigorous climatic conditions been changed by the erection of suitable and better stables in which it is possible to radically modify environment. Low temperatures, especially when accompanied by humidity, tend to increase the protective covering of animals. They also tend to arrest the development of symmetrical top and bottom lines. The Shorthorn, which stands humped up for long periods, sooner or later transmits something of its enforced curvature of the spine to its offspring. Where there is constant suf-fering on account of cold and exposure, the hair thickens, the flank rises, the rear of the animal tends to diminish, while the front end, which contains what are known as the vital organs, tends to become relatively larger. Improve the climatic conditions so that the food energy will not have to be so largely expended to maintain bodily heat, and there is a steady tendency to restore the harmony between the rear and front ends of the animal. If, in addition to improving climatic conditions, the food be improved, the change for the better becomes rapid and marked.
It should be remembered, however, that inheritance is always playing an important part, and that even favorable climate and food combined cannot radically change conformation and characteristics until long periods of time have elapsed.
Severe climatic conditions constantly tend to reduce size. Such reduction ceases only when the body structure has become adapted to all the forces acting upon it, or, in other words, when an equilibrium has been restored between energy produced and energy used. Natural forces do not respect man's wishes; they work along the lines which accomplish their purposes in the most economical way. Rigorous climatic conditions tend not only to diminish size but to eliminate highly specialized qualities and to produce hardiness - the prime characteristics which must be perpetuated if existence is maintained.
In America, serious mistakes have been made by placing some of the imported breeds under climatic conditions so much more rigorous than those to which they were accustomed as to preclude the possibility of securing expected results. Since we have become more humane in the winter-housing and treatment of animals, the breeds brought from a warmer climate than that in which they are placed in the States preserve their specialized qualities intact under skilful management. Still, there is always danger in moving animals from one climate to another radically different, especially if it be from a warmer to a colder one.