n] 



BUD OF HORSE-CHESTNUT 



15 



I. 



the effects of frost, rain, &c., and especially to prevent any 

 excessive loss of water during periods when the air is dry, 

 and particularly when winds are passing through the trees, 

 since such loss of water at a time when the interior of the 

 plant and the roots are not capable of replacing it would 

 lead inevitably to the death of the delicate tissues of the 

 terminal cone and its youngest leaves in the interior of 

 the bud. 



It must not be assumed, however, that a winter bud 

 is necessarily covered with 

 such scales. The naked, or 

 scaleless buds of the Cab- 

 bage and Brussels Sprouts 

 are quite able to withstand 

 the winter, and, as we shall 

 see, naked buds occur on 

 trees and shrubs likewise, 

 e.g. the Wayfaring Tree. 



To illustrate the struc- 

 ture of a scaly bud, we may 

 dissect the large terminal bud 

 of a Horse-chestnut (Fig. 7). 

 Proceeding as before, we re- 

 move first a succession of deep 

 brown, hard, leathery, hood- 

 like scales, usually viscid with 

 a resinous secretion which 

 glues them together : these 

 bud-scales are arranged regu- 

 larly in pairs at right angles, 

 each pair partially covering 

 the next inner pair. The 

 most external pair of scales 

 are smaller than the next 



Fig. 7. Bud of Horse-chestnut 

 in vertical section, slightly en- 

 larged, m pith ; h wood ; and r 

 cortex of the shoot-axis vr of 

 the past season ; s bud-scales ; 

 I leaves ; b inflorescence in the 

 bud-state (Sa). 



