Page:Popular Science Monthly Volume 85.djvu/469

Rh As growth and multiplication are by far the most characteristic features of the living organism, it is little wonder that the fiercest antagonism centers around this point. Mitchell, one of the mildest critics, takes exception to the crystal comparison, on the ground that living matter is a mixture of substances chiefly dissolved in water, and that therefore it would be far more appropriate to take liquids as the basis for comparison.

Armstrong and Haldane, the one a chemist and the other a physiologist, and both among the most eminent in their respective professions, flatly refute the analogy. In crystal growth there is a mere piling up of simple units, and, under the proper conditions, there is no limit to the growth of the crystal. Nothing corresponding to cell division, nor to the complexity of organic growth, is ever met with. Bergson, whose knowledge of the exact sciences makes him an exceedingly competent critic, argues that whereas the living organism is composed of unlike parts and performs diverse functions, the crystal neither consists of the one nor performs the other.

Of course, Bergson repudiates Schäfer's whole hypothesis, but in this he is in agreement with many a scientific authority. For example, Professor Wilson, whose book on cell development is a classic, sums up his views in these words:

Sir William Tilden, the English chemist, is equally emphatic from the chemical standpoint. He writes:

Let it at once be stated clearly and emphatically that the ultrascientific view is based primarily upon analogy—a very valuable method provided it is not carried to excess, and provided, also, sufficient experimental data are at hand. Mendeleèff's periodic classification tended to show that cæsium, rubidium, sodium and potassium were closely allied,