THE WEB OF LIFE 47 



Iviion. But tlie essential idea of a web is that of 

 interlinking and ramifying. We can never tell 

 where a thread will lead to. If one be pulled out, 

 many are loosened. This is true of Nature through 

 and through. 



The phrase " web of life " suggests another 

 picture — the web of a spider — often an intricate 

 system, with part dehcately bound to part, so that 

 the whole system is made one. " The quivering 

 fly entangled in a corner betrays itself throughout 

 the web ; often it is felt rather than seen by the 

 lurking spinner. So in the substantial fabric of 

 the world part is bound to part. In wind and 

 weather, or in the business of our life, we are 

 daily made aware of results whose first conditions 

 are very remote ; and chains of influence, not 

 difficult to demonstrate, link man to beast, and 

 flower to insect. The more we know of our 

 surroundings the more we realise that nature is 

 a vast system of linkages, that isolation is im- 

 possible." ^ 



Dependence op Living Creatures on their 

 Surroundings. — We do not know what life in 

 principle is, but we may describe living as action 

 and reaction between organisms and their en- 

 vironment. This is the fundamental relation — 

 the dependence of living creatures on appropriate 

 surroundings, and the primary illustrations of 

 linkages must be found here. The living creatures 

 are real, just in the same sense as the surroundings 

 are real ; but it is plain that we cannot abstract 

 the living creatures from their surroundings. 

 When we try to do this they die — even in our 

 thought of them, and our biology is only necrology. 



» "The study of Animal life," by J. Arthur Thomson (1890). 



