THE ROOT-SYSTEM OF IMPATIENS ROYLEI. 501 
Text-figure 10 shows a plant which was almost severed from its root by a 
wound at the base of the hypocotyl. Only a small portion at “а” remained 
in connection with the basal root-system. А large number of small tooth- 
like adventitious roots developed just above the wound, not only from the 
under surface, but from the upper and side regions also. The roots assumed 
a curved form as they began to grow round the stem to reach the soil. 
Unfortunately the plant died before these roots had reached the ground, and 
it was therefore impossible to tell whether or no it would have received an 
adequate water-supply from them if they had had time to develop further. 
The type of wounding shown in text-figure 9 was also commonly found. 
In the plant represented, the stem was deeply cut a little above the 
Fic. 9.—Plant showing severe wound in the first epicotyledonary internode. 
Fra. 10.— Plant wounded at the base of the hypocotyl; only a small portion at а remained 
in connection with the root-system. 
Fig. 11.—Plant showing extensive but shallow wound. Adventitious roots have developed 
from the upper side of the stem above the tear. a.r., adventitious roots. 
second node, and the weight of the plant gradually pulled the stem over at 
that point with the wound in the acute angle of the bend. The stem 
adjusted itself in such a way that the third node touched the ground and 
supported the upper portion of the plant, which assumed an approximately 
vertical position. Adventitious roots developed at this node, both above and 
below it, from the convex side ; they entered the soil and produced lateral 
roots, Thus they both anchored the plant to the ground and reinforced the 
water-supply. 
