284 LESSONS FROM NATURE. [CHAP. IX. 



forward that theory, and for forcing on men s minds a recog 

 nition of the probability, if not more, of evolution and of the 

 certainty of the action of &quot; natural selection.&quot; For though 

 the &quot; survival of the fittest&quot; is a truth which readily presents 

 itself to any one who considers the subject ; and though its 

 converse, the destruction of the least fit, was recognised 

 thousands of years ago, yet to Mr. Darwin, and (through Mr. 

 Wallace s reticence) to Mr. Darwin alone, is due the credit 

 of having first brought it prominently forward and demon 

 strated its truth in a volume which will doubtless form a 

 landmark in the domain of zoological science. 



We find even in the third edition of his Origin of 

 Species the following passages : &quot; Natural selection can act 

 only by taking advantage of slight successive variations ; 

 she can never take a leap, but must advance by short and 

 slow stages&quot; (p. 21-1). Again he says: &quot;If it could be 

 demonstrated that any complex organ existed which could 

 not possibly have been formed by numerous, successive, 

 slight modifications, my theory would absolutely break down. 

 But I can find out no such case &quot; (p. 208). He adds : 



&quot; Every detail of structure in every living creature (making some 

 little allowance for the direct action of physical conditions) may be 

 viewed, either as having been of special use to some ancestral form, 

 or as being now of special use to the descendants of this form either 

 directly, or indirectly through the complex laws of growth ;&quot; &quot; and if 

 it could be proved that any structure of any one species had been 

 formed for the exclusive good of another species, it would annihilate 

 my theory, for such could not have been produced through natural 

 selection.&quot; 



And the words last cited occur on page 1G2 of his very last 

 edition. 



It is almost impossible for Mr. Darwin to have used words 

 by which more thoroughly to stake the whole of his theory 

 on the non-existence or non-action of causes equal in efficiency 

 to natural selection. For why should such a phenomenon 

 &quot;annihilate his theory?&quot; Because the very essence of his 

 theory, as at first stated, is to recognise only the con 

 servation of minute \ variations directly beneficial to the 



