230 PLAIN AND PLEASANT TALK 



vessels, but the sap itself will be but imperfectly elaborated 

 by the leaves. We may suppose that overfeeding in vege 

 tables is, in its eifects, analogous to overfeeding in animals. 

 The sap is but imperfectly decomposed in the leaf it passes 

 into the channels for elaborated sap in a partially undigested 

 state it deposits imperfect secretions, and the whole tissue 

 resulting from it will partake of the defects of the proper 

 juice* 



Thus a too rapid growth not only enlarges the sap pas 

 sages, but forms their sides and the whole vegetable tissue 

 of imperfect matter. This accounts, not only for the perish- 

 ableness of quickly-grown timber, but, doubtless, for the 

 short-lived tendency of cultivated fruit in comparison with 

 wildings. For where the tissue is imperfectly formed, 

 general weakness must ensue. 



These reasonings do not include plants which, in their 

 original nature, have a system of large sap-vessels, etc., and 

 which naturally are rapid growers, but respects only plants 

 which have been forced to this condition by circumstances. 



Has this condition of the vegetable substance nothing to 

 do with the health of a tree? Does it not very much 

 determine its liability to disease ? its excitability ? Where 

 are trees liable to diseases of the circulation ? In England, 

 in New England, where, by climate and soil, growth is 

 slow ? or in the Western and Middle States, where, by 

 climate, by soil, and by vicious treatment, the growth is 

 excessive ? This leads me to review the methods employed 

 in rearing fruit-trees. 



The nursery business is a commercial business, and aims 

 at profit. It is the interest of nurserymen to sell largely, 

 and to bring their trees into market in the shortest possible 

 time from the planting of the seed and the setting of the 



* For the young reader it may be necessary to say, that- when sap ia 

 first taken up by the roots it is called true sap ; but after it has under 

 gone a change in the leaves it is called proper juice. 



