Two questions will at once suggest themselves. First, can it be shown that the sensitiveness to touch in various parts of the body is the result of individual experience? Have we learned to discriminate in those parts of the body that are most often brought into contact with surrounding objects? Even the power of discrimination in the tips of the fingers can be improved, as Spencer himself has shown, in the case of the blind, and of skilled compositors. Can we account in this way for the power of discrimination in various parts of the body? In other words, if, beginning in infancy, the middle of the back constantly came into contact with surrounding objects, would this region become as sensitive as the tips of the fingers? The experiment has not, of course, been carried out, but it is not probable that it would succeed. I venture this opinion on the ground of the relative number of the nerves and of the organs of touch on the back, as compared with those of the finger-tips. But, it will be asked, will not the number of the sense-organs become greater if a part is continually used by the individual? It is improbable that much improvement could be brought about in this way. The improvement that takes place through experience is probably not so much the result of the development of more sense-organs, as of better discrimination in the sensation, because the increased power can be very quickly acquired. An examination of the relative abundance of touch-spots in the skin shows that they are much more numerous in regions of greater sensitiveness. The following table, taken from Sherrington’s account of sense-organs in Schaefer’s “Textbook of Physiology,” gives the smallest distance that two points, simultaneously applied, can be recognized as such (and not simply as one impression) in different regions. Mm. Tip of tongue 1.1 Volar surface of 2.3 ungual phalanx of finger Red surface of lip 4.5 Volar face of second 4.5 phalanx Dorsal face of third 6.8 phalanx Side of tongue 9.0 Third line of tongue, 9.0 27 mm. from tip Plantar face of ungual 11.3 phalanx of first toe Palm 11.3 Back of second phalanx 11.3 of finger Forehead 22.6 Back of ankle 22.6 Back of hand 31.6 Forearm, leg 40.6 Dorsum of foot 40.6 Outer sternum 45.1