Natural History 511 



ably helped in steering by the weight of their bodies, the light- 

 ness of most insects being against good steering as they are liable 

 to be blown about by the wind. 



Whatever the pattern of wing or the speed of the wing- 

 beats, the total distance insects can fly is not great; they seldom 

 wander far afield. Some insects literally fly but once. A may- 

 fly may rise at noon from the water that cradled it, and by sun- 

 down its aerial dance of love may be over and its lifeless body 

 be floating on the surface of the pool. 



2 



Instincts and Intelligence 



Insects are largely creatures of instinct, with inborn capaci- 

 ties for doing apparently clever things, but yet with some degree 

 of intelligence. In an animal's behaviour there is often, no 

 doubt, a mingling of different kinds of activities unified in a 

 way that baffles analysis. In many cases their behaviour under 

 new conditions, their powers of effectively meeting new ends, 

 go beyond mere instinct. What are we to say of the following? 



The tailor-ants, common in warm countries, make a 

 shelter by drawing leaves together, and their co-operative 

 hauling is admirable; their mandibles are their needles, if 

 you like, but they have nothing to fix the leaves with; what 

 does each do but take a larva in its mouth so that the silk 

 secreted from the offspring serves as adhesive gum. 



The tailor-ants nest in trees, and they sometimes find 

 it difficult to bring two rather distant leaves close enough 

 together to be sewn. Then, as Bugnion relates, they have 

 recourse to a perfectly extraordinary co-operation. Five 

 or six will form a living chain to bridge the gap. The 

 waist of A is gripped in the mandibles of B, who is in turn 

 gripped by C, and so on a notable gymnastic feat. Time 

 does not appear to be of much account, but they work 

 definitely towards a result, and many chains may work to- 

 gether for hours on end trying to draw two leaves close to one 



