THE LIFE OF MATTER. 419 



Lair i>f relation (>_f specific fop ii to chein'icdt const Itutlon. — Crystalli- 

 zation is a method of aoquiririg specific form. The geometric archi- 

 tecture of the mineral individual is l)ut little less than marv(dous and 

 no less characteristic than that of the living individual. Its form is 

 the result of the mutual reactions of its substance and of the medium 

 in which it is produced; it is the condition of material eciuilihriuni cor- 

 responding to a given situation. 



This idea of a specific form that belongs to a given substance under 

 given conditions should be retained. We may consider it as a sort of 

 principle of nature, an elementary law, which may serve as a point of 

 departure for the explanation of phenomena. A particular sul)stance, 

 imder identical conditions of environment, must always assume a cer- 

 tain form. This close linking of substance to form, aduntted as a 

 l)ostidate in physical sciences, has been carried ])y some philosophical 

 naturalists, such ds M. Le Dantec, into the biological field. 



Let us imitate them for a moment. Let us cease to seek in the liv- 

 ing ])eing for the prototype of the crystal; let us on the contrary seek 

 in the crystal the prototype of the living l)eing. If we succeed in this, 

 we shall then have ol)tained a physical basis for life. Let us say, then, 

 with the biologists of whom we have l)een speaking, that the substance 

 of each living individual is peculiai- to it; that it is specific, and that 

 its form — that is to say its organization- follows from it. The mor- 

 phology of any being whatever, of an animal — of a settx'r dog, for 

 example — or even of a detei-minate being — of Peter, of Paul — is the 

 ""crystalline form of its li\'ing matter.'' It is the only foi'm of e(|ui- 

 librium that can be assumed under the given conditions by the sul)- 

 stance of the setter dog, of Peter or of Paul, just as the cube or the 

 hopper form is the crystalline form of sea salt. In this mamiei- these 

 biologists have supi)osed that they could carry back the problem of 

 living form to the problem of living substance and at the same time 

 throw back the biological mystery upon the physical mystery. 



Value of form as a cluiract eristic of li')fin<j an</ hrnte hein(js. — How- 

 ever this may be, it can be affirmed without fear of exaggeration, that 

 the crystalline form chai'acterizes the mineral with no less precision 

 than the anatomical foi-m characterizes the animal and the })lant. In 

 these two cases foriu — considered as a method* of disti'ibution of the 

 parts — signalizes the individual and allows us to diagnose it with more 

 or less facility. 



Parentage of living heings and mineral jxtroitage. — Still another 

 analogy has been noted. In animals and plants similarity in form 

 indicates similarity in descent, conununity of origin, and })roximity in 

 any scheme of classification. In the same way identity of crystalline 

 form indicates mineral relationship. Su])stances chemically analo- 

 gous show" identical, geometrically superposable forms, and are thus 

 arranged in family or generic groups recognizable at the first glance. 



