202 ECONOMY IN NATURE. 



A POPULOUS STONE. 



The economy with which God works in nature has 

 been often noticed, and especially that phase of it 

 which consists in the profusion and variety of exist- 

 ance that can be crowded and sustained in a given 

 space. A plant is growing in the earth; it occupies a 

 certain amount of room, and appears, to speak 

 loosely, to fill it. But on examination we may find 

 other plants growing on it ; its back, the angles of its 

 branches, its buds, its leaves, the interior of its blos- 

 soms, its seed-vessels — are occupied by many species 

 of spiders and insects, which find ample room for the 

 carrying on of their respective functions and the 

 enjoyment of their lives; not to speak of the birds, 

 and butterflies, and bees, and flies, that are but tem- 

 porary visitants, mere comers and goers. Many of 

 these minute animals have other creatures living on 

 them as parasites ; the earwig that is snugly enscon- 

 ced in the tube of that flower is tenanted by a long 

 intestinal worm ; yonder caterpillar so calmly gnaw- 

 ing out sinuous cavities in the edge of a leaf, sup- 

 ports within a colony of infant ichneumons ; the little 

 wild bee that has just alighted on this blossom would 

 be found to carry about sundry maggots whose black 

 heads peep out from beneath the rings of his abdomen. 

 Even the very juices that circulate in the vessels of 

 the plant probably bear along in their course the 

 germs of invisible animalcules ; for if we take the 

 leaves, or the flowers, or the stems, and make an 

 infusion of them, carefully covering the vessel to 



