86 ON CAMBIUM. 



those sheltered from its influence. Every species of re 

 straint, and, especially such as tends to render plants mo- 

 tionless, impedes their growth. Stakes by which young 

 trees are propped, nailing them to walls or trellises, 

 greenhouses, or confined situations where this salutary 

 air has not free access, check and injure the vigor of 

 vegetation, and render plants diminutive and weakly. 



Caroline. But if young trees were unsupported, they 

 would in all probability be blown down by the first vio- 

 lent wind. 



Mrs. B. The stake, it is true, is often necessary ; 

 but then it must be considered as a necessary evil, and 

 remembered that, whenever it can be avoided, the plant, 

 will thrive better without it. It should never be fasten- 

 ed so tightly as to prevent all motion, for the exercise 

 which the wind gives to young trees is no less salutary 

 than that which a mother gives to her infant ; but it is 

 true that the wind is often a rough nurse, over whom it 

 is prudent to keep a watchful eye. 



Caroline. Then nailing fruit-trees against walls must 

 be prejudicial to their growth ? 



Mrs. B. No doubt ; but the advantages resulting from 

 the shelter afforded by walls and the heat reflected by 

 them, more than compensate for the bad effects of con- 

 finement for such fruits, at least, as require a higher 

 temperature to ripen them than is to be met with in our 

 climate; but, when the temperature is genial to the 

 plant, standard trees, growing freely in their natural state, 

 produce the finest fruits. Greenhouses and hothouses, 

 however confined, are asylums necessary in winter for 

 the culture of plants of a warmer climate ; for though gen- 

 tle breezes may be beneficial to fan delicate plants, we 

 must shelter them from the inclemency of boisterous winds. 



The cambium, we have observed, descends almost 

 wholly through the liber, or most internal and youngest 

 layer of the bark ; if, therefore, you cut a ring complete- 

 ly through the bark, this fluid will be arrested in its 

 course, and, accumulating around the upper edge of the 



468. How are young trees affected when confined by stakes'? 469. 

 When stakes are necessary how should they be used! 470. What 

 advantages may result from the nailing fruit trees against walls'? 471, 

 Under what circumstances will standard trees produce the finest fruits 1 

 472. What is said of the use of Greenhouses'? 



