WINTER BUDS, SffOOTS, ETC. 



growth in length of the shoot can be determined by count- 

 ing the broad whitish scars which are situated just below 

 each pair of lateral buds. Near the margin of these scars 

 in the horse-chestnut are seen prominent pits arranged in 

 a row. These little pits in the leaf scar are formed by 

 the breaking away of the fibrovascular bundles (which 

 run into the petiole of the leaf) as the leaf falls in the 

 autumn. 



567. Lateral buds. The lateral buds, it is noticed, 

 arise in the axils of the leaves. Each one of these by 

 growth the next year, unless they remain dormant, will 

 develop a shoot or branch. Just above the junction of the 

 upper pair of branches we notice scars which rim around 

 the shoot in the form of slender rings, several quite close 

 together. These are the scars of the bud scales of the 

 previous year. By observing the location of these ring 

 scars on the stem, the age of the 'branch may be deter- 

 mined, as well as the growth in length each year. Small 

 buds may be frequently seen arising in the axils of the bud 

 scales, that is after the scales have fallen, so that four to 

 ten small buds may be counted sometimes on these very 

 narrow zones of the shoot. 



568. Bud leaves. On removing the brown scales of the 

 bud there is seen a pair of thin membranous scales which 

 are nearly colorless. Underneath these are young leaves ; 

 successive pairs lie farther in the bud, in outline similar to 

 the mature leaves, and each pair smaller than the one just 

 below it. They are very hairy, with long white woolly 

 fibres. These woolly fibres serve also to protect the young 

 leaves from the cold or from sudden changes in the tem- 

 perature, since they hold the air in their meshes very 

 securely. 



569. Opening of the buds in the spiing. As the buds 

 "swell" in the spring of the year, when the growth of 

 the young leaves and of the shoot begins, the bud scales 

 are thrown backward and soon fall away as the leaves 

 unfold, thus leaving the "ring scar" which marks the 

 start of the new year's growth in length of the shoot. 



570. A study of a number of different kinds of woody 



Fig. 399- 



shoots would serve to show us a series of very interesting f T " r S T- chtstmu 8 



variations in the color, surface markings, outline of the showing buds and leaf 



scars. (A twig with 

 branch, arrangement of the leaves and consequently dif- a terminal bud should 



ferent modes of branching, variations in the leaf scars, the 



