x Organisms and Crystals. 183 



exactly alike ; the same is probably true of the 

 physiological processes of all organisms ; and even if 

 Darwin's theory of the origin of all organic forms 

 by natural selection among spontaneous variations is 

 unsatisfactory and insufficient, he has at least made 

 it obvious that it is this fact of variability which 

 makes the evolution of organic forms possible. It is 

 asserted, no doubt, by those with whom absolute 

 determinism is an article of scientific faith, that 

 organic variations are absolutely determined, partly 

 by differences and changes in the environment of the 

 organism, and partly by the laws of its development. 

 This may be true. It is at present, and may ever 

 remain, impossible to prove either absolute deter- 

 minism, or a certain limited indeterminism, in the 

 organic world. Sabatier only insists that his opinion 

 is as tenable as that of his opponents, and that the 

 facts of organic variation give it support. 



It may be mentioned that, according to Darwin, 

 the immediate effect of a change in the environment 

 of an organism, whether animal or vegetable, is 

 usually not to produce any special variation, but to 

 promote an indefinite variability. In crystallisation 

 it is different ; when the environment of crystals is 

 changed by introducing some slight change into the 

 chemical constitution of the liquid from which they 

 are precipitated, the change in the form of the result- 

 ing crystals, if any, is definite. 



But even if we altogether reject the idea of a 

 certain limited ind^^minatioji /-in vital actions 



^ Y 



V. CALIFOV 



