PACKING AND EXPORT OF PLANTING MATERIAL. 299 



parts above ground, in order to prevent dew and rain lodging 

 on the cut surface and hastening decomposition ; for the portions 

 under ground, in order to allow water to enter the roots easily and 

 pass rapidly upwards, a jagged or spongy surface diminishing or 

 totally destroying the moisture-conducting power of the'wood-fibres. 

 This is also a reason for making an oblique section, in order to 

 allow water to flow off at once in the case of the parts above 

 ground, and to produce a large absorbing surface in the case of the 

 roots. Hence only very sharp tools should be used, such as the 

 ordinary pruning knife, a light hatchet, or a pair of garden shears 

 (Fig. 103), &c. 



The plant-parts to be pruned may have either to be merely 

 shortened or to be cut off flush with the organ that bears them. 

 Branches to be shortened must be pruned off just above a vigorous 

 bud or daughter branch. Similarly, if the leading shoot, for any 

 reason, has to be removed. In the case of conifers, the section 

 will always be just above a branch or verticel of branches, accord- 

 ing to the habit of the species. The training of one of the branches 

 of the topmost verticel as the future leader must take place after 

 the plants have been put out. In the case of bamboos, when the 

 stems are large, it is always advisable to cut off at least half the 

 entire length, and often even more, leaving only 4 or 5 knots at the 

 outside. Injured roots should be trimmed down to the required 

 length, or, if already short enough, they should be cut off just 

 above the damaged portion. Shears ought to be used only for 

 small plant-parts, not exceeding say a third of an inch in diameter; 

 the pruning knife answers for larger parts up to half an inch or 

 more, but it has this disadvantage that its use neccessitates a 

 certain amount of handling that is dangerous for roots. Hence 

 roots should generally be pruned only with shears or with a hat- 

 chet. This last must be used on a block of wood. It is the only 

 tool with which thick parts can be cut off, especially when plants 

 of some size have to be headed down. 



SECTION IX. 

 Packing and export of planting material . 



The chief danger to which all planting material, before being 

 used, is exposed is loss of moisture, which leaves the green parts 

 by the process of tr inspiration and the remaining parts in con- 

 sequence both of direct evaporation and the suction power exerted 

 by the transpiring organs. In parting with their moisture, green 

 herbaceous parts not only become flaccid and shrivel up, but their 



