physiologically considered. 69 



base, beneath the point of insertion of the petiole of the leaf. 

 Twigs that have opposite leaves should be cut in a direction per- 

 pendicular to their axis, right through the wood, either imme- 

 diately under the base of the petiole, or where its combined 

 vessels distinctly reach the stem, of which we shall speak more 

 fully in another place. Twigs that have alternate leaves should 

 have the knife inserted on the opposite side of the bud, under 

 the node, and the cut should be performed in a slanting down- 

 ward direction towards the base, or close under the point of 

 the insertion of the leaf, so as to convey away its combined 

 vessels in as perfect a state as possible, which produces the 

 same effect as when a lateral shoot is torn off and then cut clean. 

 This practice is found very successful with many cuttings, such 

 as those of camellias, banksias, and similar plants. 



This is all that seems necessary to be said of the cut, but the 

 choice of the twig admits of many modifications, the principal 

 of which we shall briefly mention. Those plants which lose their 

 leaves in winter grow the easiest from young, shoots ; among 

 which may be mentioned Punica, 2izyphus, and the different 

 species of Mimosa. Others form roots out of the full-grown 

 shoots as long as they retain their leaves, such as the different 

 species of .Spiraea. Many trees and shrubs which have a white 

 pithy wood, such as *Salix, Sj/iinga, Philadelphus, Fitis, the 

 different species of ASpirae'a, and many others, are also easily pro- 

 pagated by cuttings when it is performed late in the autumn, or 

 early in the spring, in the open ground. As soon as the sap 

 begins to flow, the buds begin to shoot out, and they then most 

 generally form roots easily and quickly. All plants which have not 

 woody stems should be propagated by young shoots ; and shrubs, 

 when they cannot be propagated by division of the root, succeed 

 as well from shoots of the first spring as from those of the second. 

 All the young shoots of plants that are only one year old may 

 be used successfully before the time of flowering. The one- 

 year's shoot of plants that have a firm woody stem and evergreen 

 leaves is the best adapted for cuttings ; but there are exceptions 

 even to this, such as the different species of Banks/a, in which 

 it is better to let the wood be two or three years old. Those 

 plants which do not always strike root from cuttings are fre- 

 quently propagated with much less trouble by layers. For this 

 purpose the plant is grown in a bed, either in a greenhouse, 

 hotbed, or quite in the open air, according to its nature. The 

 twigs are bent down on this bed, fastened to the ground, and 

 partially covered with earth. Many plants which will not strike 

 root in this way are very successfully propagated by the ring- 

 cut ; which is effected by carefully cutting away a ring in the 

 bark as far as the wood, and close under a node which is covered 

 with earth. In branches operated upon in this manner, the 



