This section is from the book "The Dogs Of Great Britain, America, And Other Countries. Their Breeding, Training, and Management in Health and Disease", by John Henry Walsh (Stonehenge). Also available from Amazon: The Dogs Of Great Britain, America And Other Countries.
The setter is, without doubt, either descended from the spaniel, or both are offshoots from the same parent stock. Originally - that is before the improvements in the gun introduced the practice of "shooting flying," - it is believed that he was merely a spaniel taught to "stop" or "set" as soon as he came upon the scent of the partridge, when a net was drawn over the covey by two men. Hence he was made to drop close to the ground, an attitude which is now unnecessary; though it is taught by some breakers, and notably to very fast dogs, who could not otherwise stop themselves quickly enough to avoid flushing. Manifestly, a dog prone on the ground allowed the net to be drawn over him better than if he was standing up; and hence the former attitude was preferred, an additional reason for its adoption being probably that it was more easily taught to a dog like the spaniel, which has not the natural cataleptic attitude of the pointer. But when "shooting flying" came into vogue, breakers made the attempt to assimilate the attitude of the setting spaniel, or "setter" as he was now called, to that of the pointer; and in process of time, and possibly also by crossing with that dog they succeeded, though, even after the lapse of more than a century, the cataleptic condition is not so fully displayed by the setter as by the pointer.
In the present day, as a rule, the standing position is preferred, though some well known breakers, and notably George Thomas, Mr. Statter's keeper, have preferred the "drop," which certainly enables a fast dog to stop himself more quickly than he could do by standing up. It is, however, attended with the disadvantage that in heather or clover a "dropped" dog cannot be seen nearly so far as if he was standing, and on one occasion, at the famous Bala trials, the celebrated Banger was lost for many minutes, having "dropped" on game in a slight hollow, strrounded by heather. As a rule, therefore, the standing position is the better one, but in such fast dogs as Ranger and Drake, "dropping" may be excnsed. At the above meeting, however, after a long and evenly balanced trial between Mr. Mac-dona's Ranger and Mr. R. J. LI. Price's Belle, the latter only won by her superior attitude on the point, and Ranger again suffered the penalty for dropping at Ipswich.