II SEPARATION OF SPECIES 27 



tions. N'either Darwin nor any other inquirer has done this 

 in a satisfactory fashion, as I remarked in the Introduction. 

 Indeed, this question has hitherto scarcely been seriously taken 

 in hand, and yet it is entitled to as much importance as the 

 s^eneral one of the causes of evolution — with its solution alone 

 have we an explanation of the origin of species in the proper 

 sense of the words. 



For the rest, it will be seen from what has been said 

 that my Theory of the Organic Growth of the living World 

 stands in complete accord with other facts and fundamental 

 considerations. Another circumstance in favour of it is that 

 it is as simple as a true principle must be. This simplicity 

 is probably the very reason that hitherto no advocate of the 

 doctrine of evolution has found words to express it. A ques- 

 tion of so extraordinarily wide a bearing seemed to demand 

 extraordinary means for its solution. Very likely, too, my 

 views, after they have overcome the usual first stage of 

 criticism, the assertion that they are unfounded, will be 

 passed on to the second usual stage, and it will be said they 

 have been long ago expressed and known, and then into the 

 third, that they are self-evident. I hope some day to rejoice 

 in the third stage, and shall rejoice even if through their 

 " self-evidence " the recognition of my own work should be 

 diminished. The second stage, however, I may help to shorten, 

 by expressly bringing forward the labours of others, and at 

 the same time discussing the differences between their views 

 and mine.^ 



Separation of the Woeld of Organic Forms into 

 Species — Genepistasis 



I have handled this subject in various zoological technical 

 papers, particularly in my memoir " On the Variation of the 



^ Compare in this respect especially the section on Lamarckism. 



