special differentiations went to the production of ears and eyes. Embryology shows that in mammals the bulb of the eye and the auditory chamber are extremely metamorphosed hair-sacs, the crystalline lens is a differentiated hair, and the aqueous and vitreous humours are liquefied dermal tissue! The implication of these wonderful facts is that sight and hearing were slowly differentiated from the sense of touch. One can seem to discern how in the history of the eye there was at first a concentration of pigment grains in a particular dermal sac, making that spot exceptionally sensitive to light; then came by slow degrees the heightened translucence, the convexity of surface, the refracting humours, and the multiplication of nerve-vesicles arranging themselves as retinal rods. And what was the result of all this for the creature in whom organs of vision were thus developed? There was an immense extension of the range, complexity, and definiteness of the adjustment of inner relations to outer relations; in other words, there was an immense increase of life. There came into existence, moreover, for those with eyes to see it, a mighty visible world that for sightless creatures had been virtually non-existent. With the further progress of organic life, the high development of the senses was attended or followed by increase of brain development and the correlative intelligence, immeasurably enlarging the scope of the correspondences between the living creature and the outer world. In the case of Man, the adjustments by which we meet the exigencies of life from day to day are largely psychical, achieved by the aid of ideal representations of environing circumstances. Our actions are guided by our theory of the situation, and it needs no illustration to show us that a true theory is an adjustment of one's ideas to the external facts, and that such adjustments are helps to successful living. The whole worth of education is directed toward cultivating the capacity of framing associations of ideas that conform to objective facts. It is thus that life is guided. [Illustration] X _Nature's Eternal Lesson is the Everlasting Reality of Religion_