i8o Charles Darwin. 



that a seed has found in its new home the same nu- 

 trition that gave rise to the original abnormal growth, 

 what will be the result ? The long-haired seeds will 

 not only be perpetuated, but will, owing to the 

 absence of a struggle with others, be more pro- 

 nounced, and the seeds presenting the most sail, to 

 use the expression, will still lead in the race, and go 

 sailing away to new fields where the competition and 

 struggle are less. Suppose these conditions prevail 

 generation after generation, and the seeds have been 

 carried by the wind over the Narrows, down on to 

 Long Island, and into Connecticut, and if after many 

 years, ages perhaps, we could compare a seed with 

 one that fell on the original field on Staten Island, 

 we should note that the wanderer had deviated from 

 the original ; that while it resembled it, it was now a 

 variety, and had taken what we might term a step in 

 the march of evolution. Now suppose that other 

 seeds from this plant where they had fallen had be- 

 come affected or influenced by some other nutritious 

 element that tended to give them a thicker coating 

 or harder case ; in others it produced a greater secre- 

 tion of some essential oil, and so on. By following 

 up their histories and finally in after ages comparing 

 all the wanderers with the primitive stock, we should 

 find that we had not one but several varieties. The 

 latter are the result of accidental conditions existing 

 throughout long or short eras of time, and this, in 

 brief, is Darwin's idea of how the diversities of life 

 have been produced. 



It will at once occur to the reader that the condi- 

 tions that might create a variation are almost endless. 



