

CHAPTER VII 



THE BEHAVIOUR OF INSECTS 



When we say that an organism is alive, we imply that its 

 behaviour differs from that of an inanimate object, such 

 as a stone. The latter is inertly submissive to the forces 

 which play upon it, whereas a living organism (or being) 

 manifests a certain awareness with respect to its sur- 

 roundings, coupled with an ability to choose between 

 expedients and to act spontaneously. Among plants 

 and the more lowly animals this mysterious quality of 

 animation is quite independent of a nervous system ; nor 

 are we justified in believing that it involves any degree of 

 consciousness. There is no ground for supposing that 

 these beings know and perceive, although many of their 

 movements are astonishingly purposeful in the sense that 

 they promote a particular end. A plant growing in an 

 ordinaiy room turns towards the window, and when 

 moved from one position to another is able to readjust 

 itself in relation to the source of light ; while in a 

 subsequent chapter we shall see that the responsive 

 movements of some insectivorous plants are even more 

 rapid and definite. Again, we may watch through the 

 microscope the extremely simple aquatic animals known 

 as Protozoa. The amoeba, for example, is a minute 

 speck of colourless jelly very similar to the white 

 corpuscles which abound in the blood-vessels of the higher 

 animals ; but unlike them it is a free unicellular being — 

 not an insignificant item in a composite structure. The 

 amoeba is a law unto itself. It creeps actively about 



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