11^ 



NURSERIES, 



engrafted into a matted net throughout the soil near 

 the hulh, and without any strong extended leaders. 

 We attributed this crowded rooting to the plants 

 having been of considerable size when put in, and 

 losing their natural leaders ; the situation, an ave- 

 nue exposed to cattle, went to confirm the probabi- 

 lity that the defect of the rooting had been owing to 

 the largeness of the plants. 



When a tree is supplied by numerous, consequent- 

 ly small and not wide-extending roots, as the tree 

 acquires size, the wide spreading branches and leafy 

 top shed off the rain and dews from the space occu- 

 pied by these roots, very few of them extending be- 

 yond this shade ; at the same time, this narrow space » 

 becomes soon exhausted of the more particular pabu- 

 lum necessary to the kind of plant, the exhaustion be- 

 ing accelerated by the dryness. This dryness and ex- 

 haustion of the soil very soon show their effects aloft ; 

 the living bark of the tree becomes covered from its 

 connexion with the air, and constricted by a thick 

 hard dead crust, which, with the consequent very 

 thin alburnum affording an inefficient communica- 

 tion between the supply and demand, react to im- 

 pair the general vigour, and particularly to impede the 

 descent of the proper sap necessary to the enlarge- 

 ment and further extension of the roots. The buds 



