THE DANGF.RS OF EXPKRIEKXE rss 



mechanically by instinct. This is an inversion of the 

 probable course of evolution : the less efficient instru- 

 ment has assigned to it by far the more difficult task. 



Apart from this prima facie objection there are solid 

 grounds for the belief that the exquisitely perfect opera- 

 tions of insects with which we are familiar arose as 

 instincts, as instincts were gradually perfected, and that 

 intelligence never came into the history at all. 



It is not from the insects which have had the most 

 varied experience of enemies, most opportunity of learning 

 by contact with danger how to avoid them, and thus of 

 developing their nervous systems through use — it is not 

 from these that existing forms have been descended, but 

 from precisely those which have had the least experience. 

 Even for ourselves experience is spoken of as ' the stern 

 guide '. To an insect she is apt to be so stern as to lose 

 all her educational value. The less an insect sees of her 

 the better the chance of existence and of representation 

 in the generations of the future. The prime necessity 

 for an insect, as for all animals which cannot in any real 

 sense contend with their foes, is to avoid experience of 

 them altoeether.^ 



This is an argument with the broadest possible appli- 

 cation to all Orders of insects. To the adaptive move- 

 ments of a beetle which when disturbed falls to the 

 ground, draws in its limbs and antennae, and looks 

 exactly like a little lump of earth ; to the alertness of a 

 fly to take wing before an enemy is within striking 

 distance ; to the perfection of all such means of defence 

 in insects, and they are numberless, we may apply the 

 words of Brow^ning : — 



Oh, the little more, and how much it is ! 

 And the little less, and what worlds away ! 



' This argument was brought forward by the present writer in the 

 discussion on Are Acquired Characters Hereditary? at the meeting of 

 Section D of the British Association, at Manchester, Sept. 5, 1887 

 {Report^ p. 755). No part of the discussion is pubHshed. The argument 

 is, however, briefly stated in Proc. Boston Society of Nat. History, vol. xxvi, 

 18955 P- 391 (reprinted in the present volume: see pp. 117, 118), and 

 also quoted in The Zoologist, Dec. 1900, pp. 551, 552. 



