174 



BUDS AND BRANCHES 



it terminates its branch. Notice the leaf scars on your 

 twig, and look for the small buds just above them. 

 These are lateral, or axillary buds, so 

 called because they spring from the axils 

 of the leaves. How many leaves did your 

 twig bear? How many ranked? What 

 difference in size do you notice between 

 the terminal and lateral buds? 



242. The Leaf Scars. Examine the leaf 

 scars with a hand lens, and observe the 

 number and position of the little dots in 

 them. (Ailanthus, varnish tree, and china 

 3 2 3 .-Youngbud tree show these very distinctly.) Refer to 

 Section 219, and say what these dots are. 



of hickory (after 

 GRAY) : t, terminal 



scl^ left' by g bud 



243. Bud Scales and Scars. Notice 

 scales of previous th t t hard sca i es by which all the 



year; s, leaf scars; 

 /,/, lenticels; tr, leaf 

 traces. 



buds are covered. Pull these away from 

 the terminal one and notice the ring of 

 scars that they leave around the base of the bud. Look 

 lower down on your twig for a ring of similar scars left 

 from last year's bud. Is there any difference in the 

 appearance of the bark above and below this ring ? If so, 

 what is it, and how do you account for it ? Is there more 

 than one of these rings of scars on your twig, and if so, 

 how many ? How old is the twig and how much did it 

 grow each year ? Has its growth been uniform or did 

 it grow more in some years than others ? 



244. Different Rates of Growth. Notice the very great 

 difference between branches in this respect. Sometimes 

 the main axis of a shoot will have lengthened from twenty 

 to fifty centimeters (eight to twenty inches) or more in a 

 single season, while some of the lateral ones will have 

 grown but an inch or two in four or five seasons. One 

 reason of this is because the terminal bud, being on one of 

 the great trunk lines of sap movement, gets a larger share 

 of nourishment than the rest, and being stronger and better 



