Active Causes of Organic Evolution 179 



"The law is, that each plant or animal produces like kind with 

 itself." His definitional statement further is wonderfully ex- 

 pressive: "Inherited constitution must ever be the chief factor 

 in determining character." But we have claimed — and nature 

 claims — a wider field for heredity than the above include, and 

 so we would suggest "the like continuity of molecular structure 

 in relation to like outgoing and incoming currents of energy, 

 so long as a body is exposed to the same environment, or to 

 an environment that, wdthin definite limits, fails to alter its 

 average constitution." 



(2) Environment. The emphasis placed on environment 

 in the above definition indicates that we would place this 

 Lamarckian factor as second to heredity in logical relation, 

 and to a large degree also in importance. And its deep sig- 

 nificance consists in its dynamic potentialities. But acceptance 

 of such a factor at once raises many and still fiercely debated 

 questions, in connection with which the terms Lamarckians, 

 Neo-Lamarckians, Spencerians, Darwinians, Weismannians, 

 Mendelians, unfortunately are freely flung about. Without 

 lingering over the merits or demerits of these "schools of the 

 prophets," however, the question may be asked: Can we or 

 can we not prove that environment "carves and chisels" every 

 organism? 



If we go back to the inorganic world we are forced to accept 

 that, unless the environment be a hermetically sealed one 

 like a drusy cavity or a closed rock fissure, environal action 

 and inorganic body-reaction are everywhere seen. The crys- 

 talline masses — whether existing as isolated or clustered crvs- 

 tals, as baked igneous rock masses, or as granitic compounds — 

 are broken up and worn away by frost or sun action, then 

 washed down by snow, rain, or water currents; the colloid 

 masses of thermal springs, of ferruginous marshes, and of 

 volcanic areas, are and have been altered by thermal, by cliemo- 

 tactic, and by electric action, or by organic agency. By such 

 agency they may be altered in their chemico-physical composi- 

 tion, so that a new body may be formed, which differs little 

 molecularly in its composition from the parent substance, as 



