After this brief excurse, let us revert to our subject. Representations become works of art only when the technique of their manufacture is perfectly controlled, at least by a number of individuals; in other words, when they are executed by one of the processes, that are industrially in common use. Where carving is practiced, we may expect artistic form in carvings; where painting, pottery, or metal work prevail, artistic form is found in the products of those industries in which the highest degree of technical skill is attained. The Eskimo carves in ivory, antler or bone, of which he makes his harpoons and many other utensils; his best representative work is made with the knife and consists of small carvings and etchings in which he applies the same methods that he employs every day. The New Zealander carves in wood, makes delicate stonework, and paints; his best representative work is made by these methods. Metal work and ivory carvings from Benin (fig. 74), headmasks from the Cameroons (fig. 75, p. 82), wood carvings from the Northwest coast of America (see figs. 154-156, pp. 184, 185), pottery from Peru, from the Yoruba country (fig. 76, p. 82), Central America and Arkansas (fig. 77, p. 85), basketry of the Pima, embroideries (see fig. 39, p. 47) and woven fabrics of the Peruvians are other examples. [Illustration: Fig. 74. Bronze casting, Benin.] [Illustration: Fig. 75. Headmask, Cross River, Cameroon.] [Illustration: Fig. 76. Terra cotta head from Ife, Yoruba country.] Since representations that are intended to have artistic value are made in the most highly developed technique it is not surprising that the formal style of the technique gains an influence over the form of the representation. The angular lines of weaving with coarse materials and the steplike forms of diagonals which are determined by this technique impress themselves often upon representations and become part and parcel of a local style. There develops an intimate relation between the formal and representative elements that brings it about that representation receives a formal value entirely apart from its significance. The deeper the influence of the formal, decorative element upon the method of representation, the more probable it becomes that formal elements attain an emotional value. An association between these two forms of art is established which leads, on the one hand to the conventionalization of representative design, on the other to the imputation of significance into formal elements. It is quite arbitrary to assume a one-sided development from the representative to the formal or _vice versa_, or even to speak of a gradual transformation of a representative form into a conventional one, because the artistic presentation itself can proceed only on the basis of the technically developed forms. At another place we shall discuss this subject more fully (see pp. 118 et seq.).