_Mastication in the industries._--Even among moderns teeth are used for many purposes other than mastication--_e. g._, for holding pins and needles and for severing cotton; also in some industries--_e. g._, among diamond workers--where it is the custom for girls to hold the diamond between their front teeth, which in consequence get much worn away, as I have myself seen. It is only among primitive peoples, however, that the jaws and teeth actually play the part of implements for use in the arts. The Australian women make lines, nets, and bags by chewing various kinds of fibre, a process which wears down their teeth considerably and may cause them to be tender.[13] The Esquimaux are still more dependent upon the use of their teeth as implements, especially in the preparation of skins for their clothing, boats, and lines. The teeth are used to hold the skins, while the latter are being scraped, the mouth constituting, in fact, “a third hand;” and the front teeth of Esquimaux women are often by this means worn away to the merest stumps.[14] The garments of the Esquimaux, even to the boots, are made up of skins which have been laboriously chewed for this purpose by the women “inch by inch,” till they acquire a beautiful softness and flexibility, and are often, indeed, chewed again after having been dried. And we are told that the women have no objection to the task, while the children are eager to help in it on account of the blubber the skin contains; also, that in bad times the men do not object to join in the work. The lines for harpooning are prepared in a similar way from the skin of the bearded seal, and in very large quantities.[15] When we think of the quantity of skins needed for these lines, for their dress, including boots and gloves, and for their boats (although for the latter some skins are used without having first undergone chewing), it is clear that enormous quantities must be chewed. The Esquimaux men also use their teeth considerably in other work--_e. g._, in lashing the sledges together.[16] The Indians of North California use their teeth for stripping the bark from the fresh shoots employed in making their wickerwork utensils, and they also employ their teeth in making strings, cords, and nets. THE INSTINCT TO MASTICATE