THE SCHOOL OF AGRICULTURE. 1 83 



ioth. Ditches; their formation, and the man- 

 ner of covering the declivities, and crowning 

 them with hedges. 



The choice of these examples exhibits the dif- 

 ferent processes of cultivation, and the experi- 

 ments most proper to throw light on the pheno- 

 mena of vegetation. But their utility cannot be 

 appreciated without attentive examination, de- 

 tailed comparison, and explanations of the man- 

 ner in which they have been brought to perfec- 

 tion. Their distribution forms an assemblage of 

 objects, pleasing by their contrasts and instructive 

 by their analogies. 



In the models of pruning we see side by side 

 the forms of the distaff, the sphere, the bush, the 

 vase, the fan, the espalier and the arc(i) ; and 

 also the methods of hastening the maturity of 

 fruit and preventing its untimely fall, by re- 

 moving a ring of bark from the branch, or inter- 

 rupting the course of the sap by ligatures. 



Among the grafts are seen trees joined by their 

 trunks, so that a single summit is nourished by 

 four or five stocks : others with their branches 

 curved and united, so as to form arbours covered 



(1) This method, which consists in bending the branches into a semi 

 circle to divert the course of the sap, has been abandoned; its result 

 is a surprising fecundity at first, but after the second year the curved 

 branches become sterile, and the stock decays. 



