' THE ORIGIN OF SPECIES ' 1 1 1 



another, with the remains of just such undifferentiated 

 family starting-points. 



Stress has mainly been laid, in this brief and neces- 

 sarily imperfect abstract, on the essentially Darwinian 

 principle of natural selection. But Darwin did not 

 himself attribute everything to this potent factor in the 

 moulding of species. 'I am convinced,' he wrote 

 pointedly in the introduction to his first edition, ' that 

 natural selection has been the main but not the exclusive 

 means of modification.' He attributed considerable 

 importance as well to the Lamarckian principle of use 

 and disuse, already so fully insisted upon before him by 

 Mr. Herbert Spencer. The chief factors in his compound 

 theory, as given in his own words at the end of his work, 

 areas follows : { Growth with Reproduction ; Inheritance, 

 which is almost implied by reproduction ; Variability, 

 from the indirect and direct action of the conditions of 

 life, and from use and disuse ; a Ratio of Increase, so 

 high as to lead to a Struggle for Life, and as a conse- 

 quence to Natural Selection, entailing Divergence of 

 Character, and the Extinction of the less improved 

 forms. Thus, from the war of nature, from famine and 

 death, the most exalted object which we are capable of 

 conceiving, namely, the production of the higher 

 animals, directly follows.' 



Such was the simple and inoffensive-looking bomb- 

 shell which Darwin launched from his quiet home at 

 Down into the very midst of the teleological camp in 

 the peaceful year 1859. Subsequent generations will 

 remember the date as a crisis and turning-point in the 

 history of mankind. 



