72 



possessed of healthy and active foliage, familiarly termed " half-ripened 

 wood." 



The art of" striking " cuttings mainly consists in guarding against 

 the exhaustion of the sap of the shoot by evaporation until the roots 

 are formed to support it. 



The various expedients resorted to, such as keeping the cutting in 

 close frames, covering them with bell glasses, shading from sun, etc., 

 have for their object the preservation of the juices of the shoot. 



The reason for the adoption of these expedients being known, their 

 necessity in individual cases will be readily understood. The greatest 

 care is required in the case of young, tender cuttings, and the least 

 with those of matured wood. Cuttings of the latter frequently succeed 

 when planted in the open air without further care or attention. On the 

 other hand, a young succulent cutting, furnished with one or more 

 leaves, must be carefully guarded against excess of light and aridity. 

 Shading from bright sun will be required to prevent the foliage from 

 wilting, and its surrounding atmosphere must be sufficiently moist to 

 prevent evaporation from its surfaces. 



The great stimulants of vegetable life are heat, air, light, and mois- 

 ture, and in the management of cuttings these must be regulated with 

 care and precision. 



"Under certain conditions, cuttings will grow and will produce a few 

 leaves without any attempt at the formation of roots, while under dif- 

 ferent circumstances the same kind of cuttings will produce roots with- 

 out indicating the slightest symptoms of bud growth. Heat is the 

 active stimulant of the vital forces of plants, and when the atmosphere 

 by which they are surrounded is of a comparatively higher temperature 

 than the soil in which they are placed, the branches are excited before 

 the roots receive any impulse. On the contrary, when the soil is warmer 

 than the air, the root-forming process will be active, although the 

 branches show no indication of growth. Of course neither of these 

 conditions can continue exclusively for any lengthened period, for with- 

 out a reciprocal action all growth will in time cease. These effects 

 are frequently illustrated in tree planting in spring. Towards the lat- 

 ter portion of spring and the early part of summer the air is many de- 

 grees warmer than the soil ; the heated atmosphere excites the buds, 

 and leaves are developed j but the recently disturbed roots in the colder 

 soil have not yet been excited, and are not in a state to supply the de- 

 mands of the foliage, the juices of the tree are soon exhausted, and the 

 promised healthy growth suddenly and hopelessly checked. 



The main point of consideration, therefore, in the management of 

 cuttings, so far as mere application of heat is concerned, is to stimulate 

 into action the processes carried on in the vessels of the cutting in- 

 serted in the soil, while the upward bud growth is retarded. This is 

 secured by heating the soil and not heating the air. The rule is that 

 cuttings should be kept in an atmospherical temperature as low as the 



