278 



SYLVA FLORIFERA. 



When these galls are opened, there is found 

 in them a worm, resembling a caterpillar in 

 figure, with about twenty legs. This creature, 

 when the gall is young, is blue ; it afterwards 

 becomes greenish ; and finally, when the gall 

 becomes red, it is white. This insect seems 

 to eat in its prison more voraciously than any 

 other gall insect whatever ; for while the gall 

 increases in size, it becomes also thinner in 

 every part, so that the creature, at the proper 

 time, has but little difficulty to get out. When 

 the time of the last change of this insect draws 

 nigh, it leaves the tree, and descends to the 

 earth, where it makes its way into a proper 

 place, and then becomes a nymph, out of which 

 at a proper time issues a four-winged fly, which 

 in its turn lodges its eggs in the leaves of the 

 willow, from whence spring thousands of in- 

 sects, which become the food of birds, who, 

 in their turn are devoured by man. Thus 

 the willow assists to convert particles of earth 

 and mineral substances, first into vegetable, 

 and then into animal substance, for the sub- 

 sistence and nourishment of the human frame, 

 which in its turn is swallowed by the hungry 

 grave, 



" Where toil and poverty repose." 



