142 BOARD OF AGRICULTURE. 



We have around us an abundance of all the elements upon 

 which we daily live, but we have no power to take them in their 

 common form. If left to ourselves, we must starve in the midst 

 of plenty. The plant feeds upon these elements or their inor- 

 ganic compounds. Plants are the chemists constantly working 

 for the welfare of the animal kingdom, bringing the elements 

 within their power. If plants were destroyed, animal life would 

 cease. For though carniverous animals may destroy others of 

 the same kind, yet in the end we come back to those animals 

 that live upon the fruits of the earth. 



There are some curious adaptations in the functions of certain 

 plants that show the relationship of one kingdom to the other, 

 and this general subserviency of the lower to the higher king- 

 dom. Certain insects sting the oak and other plants to deposit 

 their eggs in their stems or leaves, and then leave them there to 

 be developed. In some cases the young insect simply bores into 

 the wood and forms a dwelling and finds food for himself. The 

 only adaptation in this case seems to be in the fitness of the 

 material in which the egg was deposited by instinct, to supply 

 the wants of the grub while actively providing for himself. But 

 what can be more curious — I might say what more wonderful — 

 than the different kinds of oak-galls, or oak-apples, which are 

 formed by the oak, wherever the egg is deposited. When the egg 

 is placed in its tissues, the oak itself, by the very law of its being, 

 diverts a portion of its material elaborated to enlarge its own 

 trunk or fill its fruit, and forms a curious dwelling-place for the 

 young insect ; and not only forms the house but furnishes food. 

 No animal, by instinct, ever fashioned a more curious structure 

 for itself or its young, than the unthinking oak forms for the 

 egg of its insect enemy that has been thrust upon it for protec- 

 tion and support. And these dwelling-places, always built alike 

 on the same kind of tree, and 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 botan- 

 ically. On some of the rose-bushes these insect houses are built 

 and ornamented; until they are almost as beautiful as the open- 

 ing 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 

 hoiised and provided for, or the empty tenement from which he 

 has escaped to a higher form of life. These are but single 



