PRESENT CRISIS IN EVOLUTIONARY THOUGHT 29 



comes to pass that some of the biologists of greatest authority 

 in the study of Mendelian heredity are led, with regard to 

 evolutiun, either to a more or less complete agnosticism, or to 

 the expression of ideas quite opposed to those of the preceding 

 generation; ideas which would almost take us back to crea- 

 tionism." (Smithson. Inst. Rpt. for 1916, p. 334.) It is, of 

 course, impossible within the limits of a single chapter to 

 convey any adequate impression of all that Mendel's epoch- 

 making achievement portends, but what has been said is 

 sufficient to give some idea of the acuteness of the crisis 

 through which the theory of organic evolution is passing as 

 a result of his discovery. In its classic forms of Lamarckism, 

 Darwinism and De-Vriesianism, the survival of the theory is 

 out of the question. Whether or not it can be rehabilitated 

 in any form whatever is a matter open to doubt. Transfixed 

 by the innumerable spears of modern objections, its extrem- 

 ity calls to mind the plight of the Lion of Lucerne. Possibly, 

 it is destined to find a rescuer in some great genius of the 

 future, but of one thing, at least, we may be perfectly certain, 

 namely, that, even if rejuvenated, it will never again resume the 

 lineaments traced by Charles Darwin. In the face of this 

 certainty, it is almost pitiful to hear the die-hards of Dar- 

 winism bolstering up a lost cause with the wretched quibble 

 that, though natural selection has been discredited as an ex- 

 planation of the differentiation of species, Darwinism "in its 

 essentials" survives intact. For, if there is any feature which, 

 beyond all else, deserves to be called an essential of Darwin's 

 system, surely it is natural selection. For Darwin it was "the 

 most important" agency of transformation (cf. "Origin of 

 Species," 6th ed., p. 5) . Apart from his hypothesis of the sum- 

 mation through inheritance of slight variations ("fluctua- 

 tions"), now completely demolished by the new science of 

 genetics, it represented his sole contribution to the philosophy 

 of transformism. It alone distinguishes Darwinism from La- 

 marckism, its prototype. Without it the "Origin of Species" 

 would be Hamlet without the Prince of Denmark. With it 



