40 SYMPODIAL GROWTH [CH. Ill 



Elm. If we examine the tip of a Lime-twig in autumn, 

 just as the leaves are falling, we find a leaf with its 

 axillary bud close behind the terminal bud of the twig ; 

 but this axillary bud is large and vigorous and will grow 

 out next spring, whereas the true terminal bud is small 

 and shrivelled, and will not grow out (compare also 

 Fig. 9). In other words, the apparent on-growth of the 

 branch next year is only apparent each annual addition 

 to the length of the branch is really the growth of a 

 lateral branch, the axis of which comes practically to 

 coincide with that of its primary axis. The totality of 

 these growths make up a Sympodium, and the mode of 

 branching is frequently termed Cymose or Definite, the 

 latter term referring to the early arrest of the primary 

 axis. 



It is of no importance whether the arrest of the true 

 terminal bud is due to exhaustion and direct death, or its 

 conversion into a thorn, tendril, flower or other organ, 

 so long as the process is normal in the species ; though 

 it is obvious we could convert any Monopodial branch- 

 system into an artificially Sympodial one by periodically 

 nipping or cutting off the terminal buds, and this is done 

 to a large extent in the pruning of fruit-trees, the curious 

 branching of which is entirely modified by the cultural 

 operations. But exactly similar effects are produced in 

 Nature by the pruning operations due to death of the 

 terminal buds or tips of branches, or the destruction of 

 whole twigs or shoots. 



