THE SPECIES 253 



insects, containing various kinds of workers and queens, is 

 covered by a thin veil consisting entirely of soldiers, which 

 support and carry one another and threateningly turn their 

 gaping jaws, swollen with poison, towards every enemy that 

 appears. 



Such a community resembles a very long worm with a 

 thick, stinging skin, and having the stream of food in its 

 interior distributed by individual animals instead of by cells. 

 In place of its organs there are large numbers of separate 

 creatures, which move forward on their own legs at the same 

 rate as the whole animal. 



By this " army " worm of the traveller ant. Nature has 

 saved us the trouble of constructing a picture of the com- 

 munity, with all the individual animals moving at the same 

 place and at the same rate — a picture such as we had to 

 make for ourselves in the case of the cabbage-white butterfly. 

 Here we have before us in a tangible form the whole com- 

 munity as a unified organism. 



COMMUNITY AND SPECIES 



Now we are in a position to compare the community and 

 species as concrete phenomena. On the one hand we have 

 the picture of the species as I presented it in the case of the 

 cabbage-white butterfly ; and, on the other, the picture of 

 the community as Nature gives it us in the traveller ant. 

 It is obvious that both structures are built in accordance 

 with plan, i.e. all the separate creatures are connected together, 

 with all their function-circles and their surrounding- world, by 

 means of a great organisation. In all of them a rule has 

 become incarnate. This incarnation is everywhere effected 

 by impulses, which are obliged to subject themselves to the 

 rules. 



We have already learnt that the impulses may obey two 



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