DECEMBER. 355 



becomes matured, the action of the leaves decreases in proportion. In 

 deciduous trees the leaves show their gradually diminishing vitality by 

 change of colour, until their assimilating powers cease entirely, when 

 they die and fall off. The same results are observable in the leaves 

 of evergreens, which are less active during the early summer than 

 those of deciduous trees, decrease more slowly, and are not altogether 

 dormant (excepting during severe frost) till April or May, at which 

 season many of the older leaves fall off, and the trees keep a kind of 

 winter for two or three weeks until the fresh growth commences. It is 

 during the latter period of the summer growth that roots are formed 

 most freely, the descending or organised sap, besides coating the cells 

 of the plant's tissues with solid matter, is likewise directed to the roots, 

 causing an elongation of the vascular system at the extreme point of 

 each rootlet ; these care called spongelets, and their office consists in 

 sucking up or absorbing from the soil the fluid matter called sap (or 

 crude sap) which is directed to the leaves, where, after being exposed 

 in their vessels to the action of light, it becomes changed by the vital 

 action of the plant, into true or organised syp, of which every part of 

 the tree and its products are formed. 



From the above short description of the growth of trees, it follows 

 that with evergreens there are two seasons during which the operation 

 of planting may be performed with the least risk of the plants suffering 

 from being removed — first, when as the young or summer's wood 

 becomes hard, the vascular system is charged with true sap, and 

 capable of quickly replacing by new roots those which had been destroyed 

 or injured by removing the plant. Evergreens are generally (as before 

 noticed) in a favourable state for this about October ; or if the summer 

 has been dry and hot, and the trees are growing on poor soils, some- 

 what earlier. At this season, too, the earth in which they are being 

 placed is warmed, and not often too wet, and thus assists in stimulating 

 the production of new roots ; and supposing the weather at the time 

 damp, or that showers intervene so as to keep the foliage moistened 

 occasionally, the chances are very much in favour of the plants quickly 

 forming new roots sufficient to supply the leaves with sap, to make 

 good their waste by evaporation ; for we must consider that all we have 

 to do is to prevent evaporation or exhalation from the leaves until such 

 time as the plant can form for itself new roots to supply the loss of 

 moisture which arises from the above causes. I never like much 

 watering at the roots at planting, considering the practice does more 

 harm than good, as I have always found that young roots are formed 

 more quickly when the soil round them is moderately dry ; but it is at 

 the same time very desirable to keep the foliage moist by frequently 

 damping the trees overhead when the weather is dry. Nor should it 

 be forgotten that, to ensure success, the soil in which the newly planted 

 tree is placed should be well pulverised, and have been exposed to the 

 action of the weather for sometime previous to placing it round the 

 roots. I am satisfied, fiom actual observation, that trees make roots 

 more freely in soil that has been well exposed to the weather for some 

 time than in earth dug from below the surface ; where practicable, 

 therefore, let the earth dug from the holes lie exposed for some weeks 



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