In each papilla are seen vascular loops (dark lines) running up from the vascular network below, the tactile corpuscles with their nerve branches (white lines) which supply the papillæ.

'That the tactile sense in the horse's foot is useful, it would be idle to deny; but that it is absolutely essential, even to safe progression, no one who has paid attention to the results of plantar neurectomy will maintain.

Tactile discrimination is so acute as to be able to interpret to the brain significant impressions produced in very rapid succession.

The buttons are labeled "a," "b," "c," etc., to "z," and an electric current over the primary wire running from a certain button (say the one labeled "a") affects only those secondary wires connected with the styles that, when excited, produce upon the particular spot of the hands of the receivers the tactile impression to be interpreted as "a."

This sense is exquisite in men, and by his nerves dispersed all over the body, perceives any tactile quality.

The organ of touch, or tactile sensibility, is the most widely extended of all the special senses, and perhaps the simplest.