66 



EXTRACTS. 



the alburnam into the leaf; but that a portion of the fluid, which has become 

 true sap in the leaves, passes from the bark into the alburuam, and there 

 joins the ascending current, and feeds the young shoots and leaves, is not 

 generally understood by gardeners; nor that the fruit is fed by similar means ; 

 nor that the sap is deposited in the alburuam, to afford materials for leaves, 

 or to feed the blossoms and young fruit of the succeeding spring. The coa- 

 gulum which gives the matter of the new layer of bark in the spring is 

 derived from the same source, though the arrangement of the vessels and 

 fibrous texture of the bark is given by the fluid which descends by the bark. — 

 T. A. Knight, Esq. — Gardener's Magazine. 



Evil Effects of Exposing Greenhouse Plants to the Open Air of 

 Great Britain, £fc. 



The practice of turning greenhouse plants out of doors in summer may be 

 necessary under particular circumstances, and with regard to certain species 

 of plants; but, in cases where greenhouses are properly constructed, and 

 solely devoted to the cultivation of plants, these will generally be found to be 

 injured, rather than benefitted, by this treatment, particularly when turned 

 out eariy in the season. Were it possible to manage greenhouse plants during 

 the winter as it could be wished, and as they require, exposing them to the 

 open air in summer would no doubt be highly beneficial to them ; but in 

 winter, fire heat being applied, a considerable degree of excitement is induced, 

 and, before the season has arrived at which they can be safely exposed to the 

 open air, they are all, or nearly all, in a state of vigorous growth. When at 

 once removed to their summer quarters, the temperature at night is often 

 so low that a complete check is given to the growth of the plants, from 

 which they seldom recover till towards the approach of autumn ; but, be- 

 coming inured to the open-air climate, they again make an effort to grow. 

 From the gross habit which they have, however, now acquired, together with 

 the lateness of the season, the shoots are seldom well matured, and the plants 

 are unable to resist the effects of frost, mildew, damp, &c, by which green- 

 house plants are liable to be injured. But when plants are retained under 

 glass during summer, both first and second growths are ripened sufficiently 

 early in the autumn ; and unless very improper excitement be applied, they 

 will remain in a state of comparative rest till the following spring, when their 

 flowers will be both more perfect, and much more abundant, than such plants 

 will produce as may have stood out the preceding summer. 



In keeping them in the greenhouse, I do not recommend the plants to be 

 kept crowded together the whole of summer. Duplicates, and the hardier 

 kinds, may very properly be removed out of doors. During summer all pos- 

 sible air should be given day and night, except during long-continued rain, 

 and the plants occasionally be syringed overhead with water, which may be 

 done beneficially any hour of the day. I mention this, from having been 

 myself sometimes cautioned never to wet the leaves of plants when the sun 

 was shining upon them. When the roots of plants thus exposed to the sun 

 can be preserved in a tolerably cool and moist state, their tops will not only 

 bear the sun, but his full influence is indispeusible to their health and vigour, 

 and the full developement of their flowers. 



Orange trees, Camellias, &c, are liable to have their foliage injured by the 

 sun, but this injufy would seldom accrue to them were they retained in the 

 house both summer and winter, and kept cool during the latter season, not 

 applying fire heat till the temperature indicated three or four degrees of frost. 

 — R. Marnock, — Ibid. 



Method of Transplanting. 

 Small plants maybe very neatly and safely transplanted from the borders. 



