and its Injluence on Vegetation. 149 



may be wished. When the natural period of rest is shortened by 

 artificial means, for the first time the call will not be so speedily 

 responded to as when the same means are uniformly persisted 

 in ; but such is the adaptiveness of plants to the circumstances 

 in which they may be placed, such even in inanimate nature 

 the almost irresistible force of habit, that forced plants become 

 so inured to premature excitement, that they will at the usual 

 period make an effort at growth independent of circumstances; 

 a fact obvious to the most superficial observer, and which ren- 

 ders the alternate resting and forcing, recommended by some, 

 one of the most unphysiological propositions ever suggested to 

 practice. 



The growing season of plants is thus changed at pleasure 

 in artificial climates by the application of a spring-like heat, and 

 much stress has justly been laid upon the manner in which it 

 ought to be applied, most considering extreme caution necessary, 

 advising to commence and proceed by almost imperceptible gra- 

 dations. In early forcing, when light is a desideratum, this ap- 

 pears necessary, but as the season advances this becomes ques- 

 tionable : if we may judge from the proceedings of Nature, she 

 often commences her most favourable seasons in a more abrupt 

 manner. A fine, genial, uninterrupted, consequently rapid spring, 

 is most favourable to the healthful developement of the organs of 

 plants ; a cold, ungenial, consequently protracted one, one of 

 the most unfavourable things that can happen : and the noble 

 trophies of Continental vegetation, where the transition from iron- 

 bound winter to luxurious spring seems but the magic transform- 

 ation of a day, exhibit none of the debility we attribute to the effect 

 of rapid excitement; considerations that render questionable the 

 very protracted spring applied to force plants generally, and 

 invite to further investigation. All this would lead to the con- 

 clusion, that all plants capable of being so treated ought to be 

 allowed a season of rest, and that a somewhat gradual application 

 of excitement to be uniformly increased is necessary until thev 

 complete the object of their growth ; and it is also evident thalt 

 they ought to be enabled to do so, in the most unhesitating and 

 vigorous manner. Nevertheless, gentle forcing is a favourite term 

 and frequent practice with many, but surely it must be erroneous. 

 To imitate successfully a propitious season is the object of all 

 forcing : therefore the question simply is, whether by gentle 

 forcing we will imitate an unfavourable one, with all its slug- 

 gish concomitants, laxity of organisation and imperfect matu- 

 ration ; or, by more decided measures, imitate one of the most 

 favourable character. 



Thus far, with regard to the application of heat in arti- 

 ficial climates, while following the track pointed out by nature, 

 we have gone hand in hand with reason, and gardeners have 



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