Since, then, the spurs are the most powerful means recognized by equitation, their employment demands moderation, intelligence, experience, justness, exactness, propriety, accuracy, equality, precision, and faith, as moral qualifications, and, as physical basis, that sine qua non, the accurate seat, without which the other qualities are of no avail. In fact, the rider needs as much equestrian tact in his heels as in the hands and fingers which manipulate the reins. The difference is that a mistake made with the hands is usually, in large measure, reparable; but an error committed with the heels will occasion disorder or revolt that is not only dangerous at the moment but may make upon the animal a moral impression that is unforgotten and may be forever irreparable.
I have already explained that the effects of the rider's legs on the horse's flanks are indirect. The muscles of propulsion are overlaid by the panniculus carnosus. On this, the pressure of the legs acts directly; but only by education is the effect of this pressure passed on to the pectoralis magnus. But the function of the panniculus carnosus is to contract at the touch of any foreign or strange object, such as an insect or a twig. The young horse, therefore, when mounted for the first time, reacts to the contact of the rider's legs as to any other annoyance. If he is uncommonly excitable, he simply raises a hind leg and makes ready to kick. Only by the process of education does the horse
