Plants as Foster-parents. 165 



upon flesh or fish. The action of securing food, in 

 both of the latter cases, is entirely on the part of 

 the young insects ; that is, they simply eat the sub- 

 stance as they find it, though not specially prepared 

 for them, as the Oak-gall is, for its inhabitant. The 

 Apple-trees are sufferers only in the loss of leaves 

 destroyed, before they have done their work for the 

 trees. There is no evidence of any relation of the 

 tree to the insect, except as being its appropriate 

 food, and in putting out its leaves at the right time ; 

 that is, before the eggs of the insect hatch. But in 

 the case of the Oaks, the Roses, the Spruces and 

 Golden-rods, and many other plants, there is a posi- 

 tive marshalling of the powers of the plants to pro- 

 vide both food and lodging for the young insect. 

 And they do this work in as regular a manner as they 

 form leaves or flowers. 



These plants act as foster-parents ; and in sup- 

 plementing the work of the parent insect, they per- 

 form the exact office of working bees in the Hon- 

 ey-bee hive. 



There are ichneumon insects, and parasitic flies, 

 that sting the caterpillars of certain moths, but do 

 it in such a way that the caterpillar lives and eats, 

 until his enemies have come to maturity at the 

 expense of his life ; or, at least, of his power to rise 

 into a higher life. It is no uncommon thing for a 

 collector to find a caterpillar bearing numerous 

 small cocoons ; — the work of his enemies, that have 

 wasted his life, — or to open a cocoon, and in place 

 of the chrysalis, to find very many smaller objects : 

 the young of insects, which have been provided for 



