LIFE AND SCIENCE 



Inanimate nature seems governed by definite 

 laws; that is, given the same conditions, the same 

 results always follow. The reactions between two 

 chemical elements under the same conditions are 

 always the same. The physical forces go their un- 

 changing ways, and are variable only as the condi- 

 tions vary. In dealing with them we know exactly 

 what to expect. We know at what degree of temper- 

 ature, under the same conditions, water will boil, 

 and at what degree of temperature it will freeze. 

 Chance and probability play no part in such matters. 

 But when we reach the world of animate nature, 

 what a contrast we behold! Here, within certain 

 limits, all is in perpetual flux and change. Living 

 bodies are never two moments the same. Variabil- 

 ity is the rule. We never know just how a living 

 body will behave, under given conditions, till we try 

 it. A late spring frost may kill nearly every bean 

 stalk or potato plant or hill of corn in your garden, 

 or nearly every shoot upon your grapevine. The 

 survivors have greater powers of resistance a 

 larger measure of that mysterious something we call 

 vitality. One horse will endure hardships and ex- 

 posures that will kill scores of others. What will 

 agitate one community will not in the same measure 

 agitate another. What will break or discourage one 

 human heart will sit much more lightly upon an- 

 other. Life introduces an element of uncertainty or 

 indeterminateness that we do not find in the inor- 

 171 



