142 Natural Theology. 



But what can be more curious, I might truly say 

 what more wonderful, than the different kinds of 

 oakrgalls or oak-apples, which are formed by the 

 oak wherever the egg is deposited ! 



When the egg is placed in its tissues, the oak 

 at once by the very law of its being diverts a 

 portion of the nutriment elaborated to enlarge its 

 own trunk or fill its fruit, and forms a curious dwell- 

 ing-place for the young insect, and not only forms 

 the house but furnishes food. No animal by in- 

 stinct ever fashioned a more curious structure for it- 

 self or its young than the unthinking oak forms for 

 the egg of its insect enemy that has been thrust 

 upon it for protection and support. And these 

 dwelling-places, though always built alike on the 

 same kind of tree for the same insect, differ accord- 

 ing to the kind of insects for which they are built. 

 Other plants present the same phenomenon, and 

 plants entirely unlike botanically. On some of the 

 rose-bushes, these insect-houses are built and orna- 

 mented until they are almost as beautiful as the 

 opening bud itself. The stalk of the golden-rod 

 forms a large ball, in, the centre of which you are 

 sure to find the larval insect housed and provided 

 for, or the empty tenement from which he has 

 escaped to a higher form of life. These are but 

 single examples of the adaptation of plants to the 

 wants of the insect tribe. But every naturalist will 

 recall a great number of kindred cases, in which the 

 plant responds to the instinct of the animal, and 

 completes, even at its own expense of vital energy, 



