In early times when the general level of culture was low, most arts were fairly wide-spread and seem to have had a fairly continuous distribution. To-day there are widely different cultures, scattered over the globe with a continuous or, in the case of the less developed, a discontinuous distribution. The widely differentiated nature of modern cultures compared with those of more primitive times raises an important question which has its political as well as its purely scientific aspect, namely, the relationship of race to invention. The argument about the intellectual capacity of primitive man can be of little value, as it is obviously impossible to estimate the comparative value of a series of inventions which have followed one another in an evolutionary scale, since it was the invention of the first boat which ultimately made the modern battleships possible.