" ^'Lindley's Theory of Horticulture. 159 



Nothing can be more simple than this; I would earnestly press 

 it on the consideration of all those concerned. I hope you will 

 attend to it in the next edition of the Hort. Brit., and in this 

 Magazine, as most of these great botanists are quite as tenacious of 

 their antiquated lore as the lawyers. What, for instance, can be 

 more absurd than the terms itiferior and superior h'mt, as applied 

 by botanists ? Yet if one were to supply proper terms for these, 

 botanists would think the world was to be turned upside down ! 

 But to return to our subject. Let us see how the sap is going 

 up and down through all the ramifications of a young healthy 

 tree. There is nothing in the unanimated creation more beau- 

 tiful than this. Nothing so worthy the attention of the philo- 

 sopher. The principle which guides it was not understood till 

 very recently, and some people say we do not even now tho- 

 roughly understand it. 



" It must have been remarked by all intelligent observers, that in the ma- 

 jority of works upon horticultural subjects, the numerous directions given in 

 any particular ramification into which the art is susceptible of being divided 

 are held together by no bond of union, and that there is no explanation of 

 their connexion with general principles, by which alone the soundness of this 

 or that rule of practice may be tested ; the reader is therefore usually obliged 

 to take the excellence of one mode of cultivation and the badness of another, 

 upon the good faith of gardening authors, without being put into possession 

 of any laws bj' which thej' may be judged of beforehand. Horticulture is, by 

 these means, rendered a very complicated subject, so that none but practised 

 gardeners can hope to pursue it successfully ; and, like all empirical things, it 

 is degraded into a code of peremptory precepts." 



Many of us old gardeners never could understand the circu- 

 lation of the vegetable fluid till the appearance of the hot-water 

 system, and here we had a complete solution of the theory at 

 once. Wherever the fire»heat had most effect, which of course 

 was at the bottom of the boiler, there circulation first commenced. 

 It is just so in trees. The heat of the sun has most power on 

 the tenderest parts of the tree, which are the tender points of the 

 shoots, and there the sap first flows ; in both cases the vacant 

 space left by the circulation is immediately filled up by the next 

 particles, and this goes on in beautiful harmony as long as the 

 stimulus is applied. The leaves let off the lighter portion of 

 the sap, as the cistern at the end of the pipes lets off the fine 

 vapour of the water so essential to healthy vegetation. As the 

 lighter portion of the sap escapes by the leaves, the rest gets 

 more dense, and is returning back to form wood and all the 

 other appendages of a tree ; just as the water in the cistern gets 

 denser by cooling, and returns to the boiler, leaving its sediment 

 along the bottom pipe. The bottom of the boiler has no power, 

 like the roots of a tree, to discharge the final sediment; and this 



nomenclature into the form of an adjective, will produce no inconvenience." 

 (^Herb, AmaryL, p. 33.) 



M 4 



