Page:Divine Selection or The Survival of the Useful.djvu/91

 impact of light to form the first eye, there would be the same requirement now. The first eye must have been formed according to the same laws and by the same forces that all subsequent ones are. The same of the ear and of every sense organ. The essential sense-faculty of the soul forms its organ of use in the body. Yet the activities of nature's elements are essential, not to form the sense directly, but to co-operate with the sense-faculty of the soul in the perfection of the material organism by use.

The eyes of the fish in Mammoth Cave are mere specks, and their nerves senseless threads, because there is no co-operation of light waves with the sense-faculty. The rudimentary eye is formed by the sense-faculty, and it is developed into complete form between the sense-faculty and the medium of light by use. The organ of any sense-faculty is formed by the sense-faculty