purpose of pointing out that the application of the wax in the most economical manner, making it go as far as possible, subject to the condition of forming prismatic cells, is a geometrical result from adopting the simplest plane and solid figures, namely, the circle and the sphere. Let me illustrate this by a single example. Suppose I gave a coppersmith a lump of copper, and said, "Make this into a bowl of given thickness, having a maximum of capacity"; my coppersmith would undoubtedly be posed. But suppose I said, "Make this into as simple a bowl as you can, and let the material be of such a thickness": he would almost certainly make it hemispherical, or nearly so, because that is the simplest form; but his hemispherical bowl would, as a matter of fact, possess the property of maximum content which I wished it to have.
It seems to me, therefore, that there may be not a few cases in which arrangements, that appear at first sight to be the result of a choice among many that might be possible, are in fact arrangements which are necessitated by geometrical conditions, or what may be equivalent to them. This consideration should make us cautious in attributing to an arbitrary will facts which might seem at first sight to warrant this conclusion. Then, again, there are phenomena in the ordinary functions of nature, having the appearance of chance, which yet are not chance in the true sense of the word, but which have strongly the appearance of it, and for which it is difficult to give any account. The manner in which plants turn toward the light is to me a profound mystery; there must be a force to produce the motion, but I do not perceive whence it can arise. And the instinct of seeking the light sometimes assumes the most wonderful form. I think I have read of a potato in a dark cellar throwing out a long sprout which extended itself till it emerged at a hole at a distance through which light entered. The power which living matter has to adapt itself to unforeseen circumstances, of which this potato may be taken as a humble instance, has very much of the appearance of choice. A limb is broken, or a skull is trepanned, and the limb becomes as strong as ever, and the skull retains whatever brain it may have had within it, in virtue of new efforts of nature exactly adapted to the wants; but these wants are such as could not have been foreseen, and could scarcely have been included in the original idea, so to speak, of the man to whom the accident has happened.
Therefore I feel that we are on very difficult and mysterious ground when discussing the place which should be assigned in nature to choice. I think that we ought to recognize the fact that many things in the edifice of nature, which might strike us at first sight as the arbitrary touches of the great Architect, may in reality be the results of geometrical or other necessity inherent in the conditions of space, or time, or matter. Nevertheless, it is difficult to believe that a creation such as we see round about us, and of which we form a part, could have