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individuals of the same species often differ slightly m the relative 

 lengths of all .their parts may be seen in many works of natural history, 

 in which careful measurements are given. These slight proportional 

 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 other- 

 wise 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 inheriting the 



manner; whilst the individuals, less favored in the same respects, will 

 have been the most liable to perish. 



IV. Fluctuating variability, clearly distinguished by 

 Darwin from II and not especially connected by him with 

 the process of evolution. 



