Apeil 10, 1914] 



SCIENCE 



527 



range of temperature ■within narrow limits in 

 the waters and throughout the earth. Even 

 more exact is the regulation of the alkalinity 

 of the ocean hy means of carbonic acid, 

 through its unique solubility and ionizing 

 power. These are but two among many ex- 

 amples of maximal efficiency in regulation. 



The renewal of matter and energy are not 

 less highly favored. The properties of water 

 ensure everywhere the highest availability of 

 supplies in the greatest number and concen- 

 tration. Further the three elements carry 

 ■with them the possibility of maximal energy 

 supplies. In some respects, indeed, the ubi- 

 quity and mobility of water and carbonic acid, 

 their presence in the sea, in the lakes and 

 streams, in the air, and in the soil, which 

 depend upon the combined action of the unique 

 solubility of carbonic acid, the unique vapor 

 tension of water, and its unique surface ten- 

 sion, seem the most remarkable of all fitnesses. 



I can not further develop these considerations 

 here, for they are too numerous and too varied, 

 but I have elsewhere treated them extensively.' 

 In truth, all the properties of water, of car- 

 bonic acid, of the compounds of carbon, hydro- 

 gen and oxygen, of the ocean, and of the 

 meteorological process, so far as the present 

 state of science permits their analysis, need to 

 be considered, for each adds to the argument. 

 Each contributes to duration, or to activity, 

 or to the phases, or compounds, or concentra- 

 tions of possible systems. Each tends to in- 

 crease rather than to restrict the possibilities 

 of mechanism, and each is the best, or nearly 

 the best, among all the kno^wn substances in 

 the world. And the ensemble of these proper- 

 ties is perfectly and extraordinarily unique. 



All of these relationships are merely physi- 

 cal, nothing about them is biological except 

 their importance. 



From such considerations there can be but 

 one conclusion : the unique ensemble of proper- 

 ties of water, carbonic acid and the three ele- 

 ments constitutes among the properties of 

 matter the fittest ensemble of characteristics 

 for durable mechanism. No other environ- 

 ment, that is to say no environment other than 

 the surface of a planet upon which water and 



7 See "Th6 Fitness of the Environment." 



carbonic acid are the primary constituents, 

 could so highly favor the widest range of dura- 

 bility and activity in the widest range of 

 material systems — in systems varying with re- 

 spect to phases, to components, and to con- 

 centrations. This environment is indeed the 

 fittest. It has a claim to the use of the super- 

 lative based upon quantitative measurement 

 and exhaustive treatment, which is altogether 

 lacking in the case of the fitness of the organ- 

 ism. For the organism, so we fondly hope, is 

 ever becoming more fit. and the law of evolu- 

 tion is the survival of the fitter. 



Yet it is only for mechanism in general, and 

 not for any special form of mechanism, 

 whether life as we know it, or a steam engine, 

 that this environment is fittest. The ocean, 

 for example, fits mechanism in general; also, 

 if you will, it fits the whale and the plankton 

 diatom, but not man or a butterfly. But, of 

 course, as everybody has known since 1859, it 

 is really the whale and the diatom which fit 

 the ocean. And this leads to the true conclu- 

 sion of our investigation. 



Just because life must manifest itself in 

 and through mechanism, just because, being 

 in this world, it must inhabit a more or less 

 durable, more or less active physico-chemical 

 system of more or less complexity in its phases, 

 components and concentrations, it is condi- 

 tioned. The inorganic, such as it is, imposes 

 certain conditions upon the organic. Accord- 

 ingly, our conclusion is this : The special char- 

 acteristics of the inorganic are the fittest for 

 those general characteristics of the organic 

 which the general characteristics of the inor- 

 ganic impose upon the organic. This is the 

 one side of reciprocal biological fitness. The 

 other side may be similarly stated: Through 

 adaptation the special characteristics of the 

 organic come to fit the special characteristics 

 of a particular environment, to fit, not any 

 planet, but a little corner of the earth. 



Lawrence J. Henderson 



Harvard Unj-tersitt 



THE PITTSBVBGH EZPEBIMENT STATION 

 OF THE BUREAU OF MINES 



Plans for the proposed $500,000 experi- 

 ment station of the United States Bureau of 



