138 



THE HAZEL. 



shed their pollen, turn brown and fall off ; 

 the latter, too, disappear, but in the course of a 

 few months may be detected, as bunches of nuts, 

 hiding themselves under the now fulJy expanded 

 foliage. At this season, a beautiful little beetle, 

 halaninus nucwn, guided by a 

 mysterious instinct? pierces the 

 yet tender shell of the nut, 

 and lays a single egg. The 

 soft pithy substance which it 

 contains, not being adapted for the sustinence of 

 the grub, the egg remains without undergoing any 

 change for some weeks ; but when the kernel has 

 nearly acquired its full size, a small white grub is 

 hatched, which immediately begins to feed on the 

 nut, and when full-grown, shews that although its 

 sole food has hitherto been of the softest kind, 

 it is provided with a powerful apparatus for gnaw- 

 ing a very hard substance. About the time that 

 the nut is ripe, the insect prepares for a change 

 of habitation, by boring a hole through the shell 

 and forcing its way out. It then falls to the 

 ground and buries itself in the earth, where it 

 constructs a cell, and is changed into a pupa, and 

 in the following season comes forth as a perfect 

 insect. We may well wonder at the instinct 

 which directs this little beetle to choose from 

 among all the trees of the forest, the one which 

 alone will afterwards bear abundance of food for 

 its offspring, and food too which it never eats 

 itself; and it is no less remarkable that it ap- 

 pears to know if the nut has been already occu- 

 pied by some other insect of the same kind, for 

 we never find two grubs inclosed in the same shell. 

 It can have gained its knowledge neither by expe- 



