468 INTERNATIONAL GARDEN CLUB 
It should be noted that in the development of the dropper the 
relative positions of the old scales and their nodes are not 
disturbed. Neither are the relative positions of the scales and 
nodes within the new bulb changed in the least. The immediate 
contact of the green leaf to the bud which it encloses is 
unchanged at the lowest side, and the relation of this same leaf 
to the scales outside of it is unchanged at the outside at the 
upper level. In the development of the dropper of the tulip 
plant, therefore, the shape of the basal portion of the green 
leaf, the shape of its node, the shape of the internode immedi- 
ately above, and that of the internode immediately below have 
become greatly distorted. No other parts are directly in- 
volved in the growth of the dropper. 
The methods of growth here concerned may be compared 
to the more usual methods of growth seen in stems. Stems 
increase in diameter and also in length. When the radial 
growth is uniformly concentric and the elongation is quite the 
same for all nodes and internodes there is produced a sym- 
metrical and gradually tapering cone-shaped stem, as is the 
- rule in most shrubs and trees. This condition can be illus- 
trated by the diagram of figure 14. When a tulip plant 
sends up a flowering stalk there is a marked elongation of 
internodes and the radial and longitudinal growth i is decidedly 
uniform as is shown in figure 21. When a series of nodes and 
internodes grows to a diameter greater than that of the inter- 
nodes behind them, as is represented in figure 15, such swollen 
stems as the tubers of the potato may result. When the radial 
growth of an internode is concentric but the elongation is 
not uniform the direction of the apex is changed; a result very 
commonly attained in plants of all sorts. 
If there is a decided eccentric radial growth in a single node 
and in the parts of the internode below it, but a rather uni- 
form elongation throughout, the result would be as represented 
in figure 16. But if at the same time there is unequal elonga- 
tion of the internode below and its greatest elongation is on 
the side of the greatest radial growth of the node above, some 
such figure as is shown in 17 will result. 
