INTRODUCTION. XXV11 



takes place before they can be replaced, a plant must 

 necessarily die. This is the reason why deciduous 

 trees cannot be transplanted when in leaf; it is im- 

 possible to remove them without injuring their spon- 

 gioles, and it is equally impossible to hinder the evapo- 

 ration by their leaves : but if they are kept in pots, it 

 matters not at what season their removal takes place, 

 because as their spongioles are then uninjured, even 

 excessive evaporation would be made good by their 

 action. It is well known that certain evergreens, such 

 as Hollies, Laurels, &c. can be transplanted in almost all 

 months ; this arises from their perspiration being much 

 less copious than in deciduous trees, wherefore the spon- 

 gioles have less difficulty in supplying the^ loss occa- 

 sioned by it ; yet even evergreens cannot be removed in 

 the hottest months in the year, because then the action 

 of such spongioles as may be saved in the operation 

 would not be sufficient to supply the waste by eva- 

 poration. Plants first beginning to grow in the spring, 

 with their leaves just turning green, are in a most unfit 

 state to remove ; for, when transplanted, their roots will 

 not have time to form a sufficient number of new 

 spongioles to supply the loss to which the rapid pers- 

 piration by the leaves at that season will give rise. It is 

 upon this same principle, that if deciduous plants are 

 taken from the ground in the summer, they are put 

 into pots and placed in a hot-bed to recover ; not for 

 the sake of the heat, but because the atmosphere of a 

 hot-bed is so charged with humidity that perspiration 

 cannot go on, so that the vital energies of the plant, 

 instead of being wasted by evaporation, are directed to 

 the formation of new mouths by which to feed. 



This is but a brief outline of what the principles are 

 upon which the common operations of the Fruit 

 Garden depend ; yet it is hoped that it may not be 

 without its use in calling attention to the rationaiia of 



