CHAP. Ill The Struggle of Life 35 



marvellous strength, and hedgehog and porcupine have 

 their hair hardened into spines and quills. Now we do not 

 say that all these structures were from the first of the 

 nature of armour, indeed they admit of other explanations, 

 but that they serve as armour now there can be no doubt. 

 And just as we conclude that a man would not wear 

 a chain shirt without due reason, so we argue from the 

 prevalence of animal armour to the reality of struggle. 



For a moment let me delay to explain the two saving- 

 clauses which I have inserted. The pincers of a crab are 

 modified legs, the sting of a bee has probably the same 

 origin, and it is likely that most weapons originally served 

 some other than offensive purpose. We hear of spears 

 becoming pruning-hooks ; the reverse has sometimes been 

 true alike of animals and of men. By sheer use a structure 

 not originally a weapon became strong to slay ; for there 

 is a profound biological truth in the French proverb : " A 

 force de forger on deviettt forgeron." 



And again as to armour, it is, or was, well known that a 

 boy's hand often smitten by the '« tawse " became callous as 

 to its epidermis. Now that callousness was not a device — 

 providential or otherwise — to save the youth from the pains 

 of chastisement, and yet it had that effect. By bearing 

 blows one naturally and necessarily becomes thick-skinned. 

 Moreover, the epidermic callousness referred to might be 

 acquired by work or play altogether apart from school 

 discipline, though it might also be the effect of the blows. 

 In the same way many structures which are most useful as 

 armour may be the "mechanical" or natural results of 

 what they afterwards help to obviate, or they may arise 

 quite apart from their future significance. 



3- Different Forms of Struggle. — If you ask why 

 animals do not live at peace, I answer, more Scotfico, 

 Why do not we ? The desires of animals conflict with 

 those of their neighbours, hence the struggle for bread 

 and the competition for mates. Hunger and love solve 

 the world's problems. Mouths have to be filled, but 

 population tends locally and temporarily to outrun the 

 means of subsistence, and the question "which mouths'' 



