THE WAYS OF LIFE 227 



bracken. This and that interpretation may be fallacious, 

 but there is no doubt as to the profitable nature of the 

 inquiry. 



LIMITATIONS OF INSTINCT 



Wonderful as instinctive achievements are, they are 

 much more limited than those of intelligence. They are 

 tied down to particular forms and sequences, and even a 

 slight change or dislocation makes them futile. A good 

 example of this limitation of instinct is given by Fabre, who 

 states that when the nest of the common wasp is covered 

 with a bell glass, the imprisoned insects never dig a passage 

 out, though they could if they tried, but remain cooped up 

 till they die. Moreover, although stragglers which had 

 been left outside will actually dig their way in, they have 

 not wit enough to show their fellows the way out, nor 

 even to make their own escape again. Instinct is always 

 fatalistic. 



The mason bee makes a mortar nest with a lid, through 

 which, at the proper time, the grub cuts its way. Put 

 on a little paper cap in actual contact with the lid, and the 

 grub has no difficulty in cutting through the extra layer. 

 But if the covering cap be fixed on just a little way above 

 the natural lid, not in contact with it, the grub emerging 

 into the closed interval between the lid it has cut through 

 and the artificial covering cap, can do no more, and dies. 

 It could cut its way through with the greatest of ease, but it 

 cannot. For when it has emerged through the first lid 

 it has done all its cutting, and it cannot repeat it. So, the 

 routine having been disturbed, it dies in its paper prison, 

 for lack of the least glimmer of intelligence. 



