In the fall of the year, the farmers and the ranchers of the northwest prairies of Canada release their horses for the winter. Strange as it may seem to those of us who shudder at the very thought of raging blizzards on the open plains, the horses that are left free to roam over unsheltered space and are obliged to dig down through feet of snow for their grass, not only survive the severest winters but are generally found fat and strong the next spring.