92 GENERATION OF INSECTS 



in two ways. One way is that the worms come in from 

 outside, and, seeking food, gnaw a path to the very heart 

 of the fruit and the wood. The other way, which I 

 esteem worthy of credence, is to be found in the pecuHar 

 potency of that soul or principle which creates the flowers 

 and fruits of living plants, and is the same that produces 

 the worms of these plants. Who knows ? Perhaps many 

 of the fruits of trees are produced with a secondary, 

 rather than a primary purpose, not as pre-eminent in 

 themselves, but as objects of utility, destined as a matrix 

 for the generation of these worms, which remain in them 

 for a determined length of time, and thence come forth 

 to enjoy the sunshine. 



I think that my idea will not seem paradoxical to you, 

 if you consider the great variety of growths, such as 

 glands, galls, knobs, warts, etc., produced by oaks, holm 

 oaks, live oaks, and other acorn-bearing trees. In the 

 hairy tufts of the oak, and in the woody tufts of the ilex, 

 and in the galls of the holm oak leaf, it is manifest that 

 the first and principal intention of Nature is to create 

 therein a winged animal, for there is an tgg in the in- 

 terior of the gall, and this egg enlarges and matures in 

 proportion to the development of the gall, and finally 

 gives birth to the worm, which, when the gall has reached 

 maturity, becomes a fly, that breaking the egg and com- 

 mencing to gnaw the gall, makes a narrow and always 

 round road from the center to the circumference, and 

 abandoning its native prison, escapes and flies boldly 

 away in search of food. 



I confess to you frankly that before making these ex- 

 periments in the generation of insects I believed, or 

 rather suspected, that galls were originated by the fly, 

 which, in the Spring, makes a small slit in the young 



