176 



BUDS AND BRANCHES 



325. — Opposite- 

 leaved twig of 

 horse-chestnut. 



ing all the points that 'were brought out in the examination 

 of your previous specimen. Which is the larger, the lateral 

 or the terminal bud ? (If lilac is used, there 

 will probably be no terminal bud.) Is their 

 arrangement alternate or opposite ? What 

 was the leaf arrangement .'' Count the dots 

 in the leaf scars ; are they the same in all } 

 If all the buds had developed into branches, 

 how many would spring from a node .'' 

 Look for the rings of scars left by the last 

 season's bud scales. Do you find any twig 

 of more than one year's growth, as measured 

 by the scar rings ? 



Look down between the forks of a 

 branched stem for a round scar. This is not a leaf scar, 

 as we can see by its shape, but one left by the last season's 

 flower cluster. The flower, as we all know, dies after 

 perfecting its fruit, and so a flower bud can not continue 

 the growth of its axis, as other buds do, but has just the 

 opposite effect and stops all further growth in that direc- 

 tion. Hence, stems and branches that end in a flower 

 bud can never develop either excurrent 

 or ordinary dehqvtescent growth, but 

 are characterized by short branches 

 and frequent forking. The same thing 

 happens when, for any reason, the 

 terminal bud is destroyed or injured 

 either artificially, or through natural 

 processes, as in the lilac, where it 

 is frequently aborted and its place 

 usurped by the two nearest lateral 

 ones, which put forth on each side of 

 it and continue the growth of the 

 branch in two forks instead of a single axis. This gives 

 rise to the kind of branching which we see exemplified in 

 the lilac, buckeye, horse-chestnut, dogwood, jimson weed, 

 etc., designated by botanists as dicliotomous, or two-forked. 

 Draw a diagram of the buckeye, or other dichotomous 



326. — Diagrams of dichot- 

 omous branching. 



