504 MISS ISABEL MCCLATCHIE ON 
2. Experiments on Older Plants. 
A. Solitary healthy plants. 
(a) Main acis.—len plants were grown in an open situation and were 
surrounded, up to their fourth nodes, by a large cone of soil. 
Results. 
In all cases roots developed ail round the hypocotyl. In five cases they 
occurred in the lower half of the first internode, and in three cases in the 
upper half also. In two plants they developed throughout the second and 
third internodes also. 
(0) Lateral branches.—Kight large plants were surrounded by soil to just 
above their first lateral branches, and these were pegged down to the sur- 
rounding soil so that the basal swelling and the first branch-node were below 
the soil and the second branch-node touched it. 
Results. 
In all cases many roots developed from the basal swellings of the lateral 
branches ; they grew downwards into the soil, producing many lateral roots. 
Five plants showed a number of roots from the first branch-node. 
Two plants showed one root at the first branch-node. 
One plant showed traces of a single root at the first branch-node. 
(c) Experiment (5) was repeated with higher lateral branches. 
Results. 
Negative results, except for roots from the basal swellings. 
B. Plauts taken from the crowded areas. 
(a)—At the end of June а row of ten plants was buried in soil to a height 
of seventy-five centimetres, so leaving about thirty centimetres exposed. Аз 
the plants grew, soil was added, so that the length of the exposed portion 
remained approximately the same. The soil by which the plants were 
surrounded was banked up against a wall about four metres high, which 
ran almost due east to west, and the plants were in a row parallel to the wall 
and at a distance of half а metre from it. They were lelt undisturbed until 
the end of September. 
Results. 
In all plants there was a profuse adventitious-root development from the 
main axis. The lateral branches either died or were too feeble to bear roots. 
(i.) In all cases roots developed at the first (cotyledonary) and second 
nodes. 
(11.) In ten cases roots developed at the third nodes. 
(111.) In eight cases roots developed at the fourth nodes. 
(iv.) In one case roots developed from the fifth node. 
