DARWIN 



careful measurements are given. These slight propor- 

 tional differences, due to the laws of growth and 

 variation, are not of the slightest use or importance 

 to most species. But it will have been otherwise with 

 the nascent giraffe, considering its probable habits of 

 life; for those individuals which had some one part or 

 several parts of their bodies rather more elongated 

 than usual, would generally have survived. These 

 will have intercrossed and left offspring, either in- 

 heriting the same bodily peculiarities, or with a ten- 

 dency to vary again in the same manner; whilst the 

 individuals, less favoured in the same respects, will 

 have been the most liable to perish.""^ It is almost 

 inconceivable that a great man should have rested his 

 case on an argument so easy to tear to pieces. In the 

 first place, he says the giraffe may have a tendency to 

 vary and yet he writes to Hooker: "Heaven forfend 

 me from the Lamarck nonsense of a tendency to pro- 

 gression^'' and he again and again writes to his friends 

 that a "tendency to vary" is fatal to his theory, as it 

 is equivalent to assuming unknown forces which act 

 according to Design. 



It is not difficult to make a picture of Darwin's 

 idea. During a period of great scarcity of food all the 

 easily accessible leaves have been used; the margin is 

 so close that individual giraffes which happen to have 

 an extra inch of length in the neck have a great ad- 

 vantage and will more probably survive and produce 



23 Or-gin of Species, vol. I, p. 277. 



C 225 3 



