42 



THE OAK. 



In this case, as in many others^ truth is stranger 

 than fiction." It not unfrequently happens that 

 one of the ichneumon flies lays an egg in the body 

 of the original inhabitant of one of these cells. 

 From this egg proceeds a small worm, which lives 

 on the substance of its predecessor, inhabits his 

 house, and, when grown to a perfect insect, es- 

 capes and takes flight in search of a similar abode 

 for its own progeny. What faculty, or sense, 

 or instinct, can this little animal possess, w^hich 

 directs it to a solid vegetable substance, in the 

 centre of which is stored up proper nourishment 

 for its young ? What geometrical skill enables it 

 to discover in what part of the mass its prey lies 

 buried ? By the aid of what calculating power 

 does it contrive to pierce the body of the included 

 grub only so deep as to deposit its egg in a place 

 of security, without wounding any vital part ? If 

 old Gerard had been acquainted with these facts, 

 he would surely have thought them more won- 

 derful than all his absurdly superstitious fancies, 

 which he could scarcely have been so foolish as to 

 believe when he wrote them down. 



The most remarkable kind of Oak-gall, next to 

 that described, is produced by another insect of 

 the same genus (Cynips), This fly deposits its 

 eggs in the stalk of the stamen-bearing flowers, 

 which is long and drooping. The excrescence 

 which follows resembles a currant in size, shape, 

 and even in mode of growth, it often happening 

 that several are placed at short distances from 

 each other on the same thread-like stem. There 

 is a remarkable fact connected with this species 

 of gall. Those flowers of the Oak which bear 

 stamens only are destined to wither and fall off* 



