WAYS OF NATURE 



would go through and then try to pull them after 

 him. All night he or his companion seems to have 

 kept up this futile attempt, fumbling and dropping 

 the nut every few minutes. It never occurred to the 

 mouse to gnaw the hole larger, as it would instantly 

 have done had the hole been too small to admit its 

 own body. It could not project its mind thus far; 

 it could not get out of itself sufficiently to regard 

 the nut in its relation to the hole, and it is doubtful 

 if any four-footed animal is capable of that degree 

 of reflection and comparison. Nothing in its own 

 life or in the life of its ancestors had prepared it to 

 meet that kind of a difficulty with nuts. And yet 

 the writer who made the above observation says 

 that when confined in a box, the sides of which are 

 of unequal thickness, the deer mouse, on attempt- 

 ing to gnaw out, almost invariably attacks the thin- 

 nest side. How does he know which is the thinnest 

 side ? Probably by a delicate and trained sense of 

 feeling or hearing. In gnawing through obstruc- 

 tions from within, or from without, he and his kind 

 have had ample experience. 



Now when we come to insects, we find that the 

 above inferences do not hold. It has been observed 

 that when a solitary wasp finds its hole in the ground 

 too small to admit the spider or other insect which 

 it has brought, it falls to and enlarges it. In this 

 and in other respects certain insects seem to take 

 the step of reason that quadrupeds are incapable of. 

 164 



