76 
THE PLANT WORLD. 
tically no seed was set at the time when the field was seen, and 
it was soon after plowed. 
While the individual growing point functions as the normal 
tip for the growth unit it bears, these units are not developed 
upon all sides of the axis except in the rudimentary stage. As 
soon as they are large enough to be recognized as bud or leaf 
units, they rotate upon their axes so as to bring their further 
Fig. 38. Part of Fig. 37 enlarged to show character of the rudiments of 
buds, and the hairy covering of the young parts. .S', stipules; 
B, buds; L, leaf rudiment. 
development upon the outside of the stem; this is shown in the 
pen drawing (Figs. 2, 3). This is likely to be in response to 
the light stimulus, and results in the concentration of all the units 
upon the outer edge of the rim, where they form a fringe-like 
apex to the stem. This is shown in the stems photographed as 
PI. 3, especially the two at the left. In Figs. 2 and 3 the inner 
side of the rim is toward the lower right hand, with the growing 
