W. H. Burroughs, Haney's Art of Training Animals
“ Still any animal of ordinary capacity ought, with proper tuition, to be able to learn a sufficient variety to satisfy 15a reasonable trainer. Judicious management on the part of the exhibitor will often make a variety of tricks out of a single one which the animal has been taught; an example of this is afforded by the “educated hog.”The first essential for success in training animals is patience. ”
