110 SYMPODIAL AND MONOPODIAL BRANCHING, 
fact that here the apparent primary axis consists of a succession 
of secondary axes. 
In sympodial branching, again, the sympodium may be 
either formed of the fork-branches of the same side (left or 
right) of successive dichotomies (fig. 216, A, I, 1, 1); or it may 
consist alternately of the left and right fork-branches or bifur- 
cations (fig. 216, B, 1, 7,1, 7). In the former case it is called 
helicoid or bostrycoid dichotomy ; in the latter, scorpioid or cicimal 
dichotomy. 
Of the monopodial branching there are also two forms, the 
racemose and the cymose. In the first the primary axis continues 
to develop upwards and gives off acropetally lateral branches 
from axillary buds; which also give off lateral branches in a 
similar manner; but in the second form the lateral axes at an 
early age develop much more vigorously than the primary axis 
and become more branched than it. IJt is in this way—that in 
some plants, by the suppression of the terminal bud, and the 
subsequent vigorous growth of the closely arranged lateral buds 
forming two shoots apparently radiating from a common point, 
as if caused by the division of the terminal bud, as in true 
dichotomous branching—an apparent but false dichotomy is 
produced, which is called a dichasiwm or false cyme. This sup- 
pression of the terminal bud may occur naturally, as in the 
Lilac (fig. 209), or accidentally from frost or other injury. 
These modes of branching will be again alluded to under the 
head of Inflorescence, in which their more practical application 
arises. 
All lateral or axillary buds are called regular or normal, and 
their arrangement in such cases is necessarily the same as that 
of the leaves. Again, as branches are formed from buds thus 
placed, it should foliow that their arrangement should also cor- 
respond to that of the leaves. This corresponding symmetry, 
however, between the arrangement of the branches and that of 
the leaves is interfered with from various causes. Thus, in the 
first place, by many of the regular buds not being developed, 
Secondly, by the development of other buds which arise irregu- 
larly at various other points than the axils of leaves: these are 
called, from their abnormal origin, adventitious. And, thirdly, 
by the formation of accessory buds. 
1. Non-development of the Regular Buds.—This frequently 
takes place irregularly, and is then altogether owing to local or 
special causes ; thus, want of light, too much crowding, or bad 
soil, may cause many buds to become abortive, or to perish 
after having acquired a slight development. In other instances, 
however, this non-development of the buds takes place in the 
most regular manner ; thus, in Firs, where the leaves are very 
closely arranged in a spiral manner, the branches, instead of 
presenting a similar arrangement, are placed in circles around 
the axis, at distant intervals. This arises from the non-deve- 
