48 



THE GARDENER. 



when they come in contaet with the earth, that they 

 become layered without care ; others require to be 

 pegged down to the earth, but not earthed. If cut- 

 tings or slips be taken from plants that haye leaves 

 and stems, and set in earth under suitable circum- 

 stances as to heat and moisture, the sap which they 

 contain will enable them to push out roots and buds, 

 from which will issue the leaves, designed to perform 

 their proper functions in establishing the independent 

 existence of these fractional portions of plants. 



This wonderful support of vegetable life enables 

 some plants to reproduce themselves, through their 

 leaves alone ; if their stalks or petioles be set in nu- 

 tritive mould, and with sufficient heat and moisture, 

 they will root ; and the leaves of most of the succulent 

 plants, if laid on earth, with the upper side to the light, 

 will root sooner or later.* 



The theory of this, however, is not exactly deter- 

 mined ; the vegetation may arise from the organizing 

 power of the sap, rather than the general diffusion 

 through the plant of embryo buds. 



The nature and properties of the sap fluids being 

 so far explained, I may proceed to the subject of 

 pruning and training fruit trees, which are among the 

 most difficult and important branches of the gardener's 

 education. 



Pruning affords one of the numerous evidences of 

 that universal law of the Creator, by which his gifts 

 are to be improved and extended by the industry and 

 ingenuity of man. Experience and science have 

 brought the art to a wonderful degree of perfection, 

 and caused the abandonment of many errors in which 

 our forefathers were involved. But as, with the am- 

 putating knife or lancet in the hands of an unskilful 

 surgeon, a great or irremediable injury may be done 



♦ See Loudon's Suburban Horticulturist 



