CHAP. VIII Spring and its Studies 157 



are usually situated in the axils of leaves, develop and 

 shoot forth as leaf-bearing branches or as flowers. 



In our common trees, and indeed in most of the per- 

 ennial plants of temperate climates, the buds are well 

 formed in autumn. For a time there is active growth, but 

 this is checked by the advent of winter, during which the 

 buds remain dormant. When the frost is unusually keen 

 the tender life of the bud is sometimes killed, but this is 

 usually obviated by the protective scales with which the 

 bud is enclosed. Just as the outer older leaves of the 

 cabbage envelop the inner leaves, so is it in the bud. But 

 there is more than this ; the outer parts are modified — by 

 an arrest of development, or even partial dying — into firm 

 scales, which are often waterproofed with an exudation of 

 resinous varnish, or warmly lined with epidermic down. 

 Moreover, the inner leaves of the bud are kept close 

 together, bent over the growing point of the stem, for it 

 seems that at first their under surfaces grow more rapidly 

 than the upper surfaces — the very reverse of what after- 

 wards takes place when the buds burst and the leaves 

 unfold. 



Bud-Scales. — If we look at a number of buds we see 

 various arrangements which secure their better protection 

 against the cold of winter. In the simplest cases, e.g. 

 lilac and rhododendron, the bud - scales are modifica- 

 tions of entire leaves : in fact, in a notably exceptional 

 case among our deciduous trees, that of the Wayfaring 

 tree ( Viburmim Lanta7ia\ the lowest leaves serve as bud- 

 scales — that is, the bud-scales, thanks to their woolly coating, 

 are able to survive and develop as ordinary foliage leaves. 

 In other cases, they correspond simply to the broadened 

 stalks of leaves, and if we examine branches of the horse- 

 chestnut or walnut in spring we shall find occasional 

 examples of every stage between the foliage-leaf with its 



