26 KINDS OF BUDS [CH. 



These cases remind us of others which show that 

 although the axillary position of lateral buds is so common 

 among the higher plants as to be considered the normal, 

 there are plenty of more or less evident exceptions. In 

 the Beech, for example, the buds are laterally displaced 

 from the axil, and still more so in Monstera and other 

 Aroids. 



Several trees have buds accessory to the axillary bud, 

 and either superposed vertically above the latter (Ash, 

 Aristolochia Sipho, Lo nicer a Tartar ica, Juglans cinerea, 

 Hornbeam, Sambucus racemosa, and S. nigra, Cercis gymno- 

 cladus and others), or placed laterally to it, as occurs in 

 Quercus ilicifolia, Salix nigricans, Hawthorn, Red Maple, 

 &c. In Gleditschia the superposed buds are very small 

 and immersed. 



In most cases the buds are placed directly in the axil, 

 however, and closely sessile in it : the stalked lateral buds 

 of the Alder owe their peculiarity to a slight growth of 

 the shoot below the oldest bud- scale, a phenomenon which 

 brings home to us the fact that the axillary bud is, after 

 all, but the undeveloped branch. 



Each branch, in fact, arises by the development of 

 a bud, just as the whole shoot-system results from the 

 extension of the plumule, or primary bud of the seedling. 

 It follows that we may find buds of different kinds on the 

 plant. In some cases the bud contains foliage leaves only 

 arranged round the tip of the axis, and we may term these 

 Leaf-buds ; while other buds contain both ordinary leaves 

 and flowers, and are called Mixed buds : others, again, 

 may be Flower-buds. The differences between those buds 

 which contain flowers and those which contain leaves only 

 are well seen in Cornus mas, Poplars, and in some of our 

 fruit trees, and the art of pruning these latter depends on 

 a knowledge of these facts. 



