130 
Holden . — Further Observations on the Wound 
dependent on the proximity of the vascular strands, and there appears to 
be no satisfactory explanation of its occurrence. 
In some few cases the stimulus of wounding seems to have produced 
very far-reaching results, and to have caused elongation through quite 
a large part of the cortex. Such a case is illustrated by Fig. 3, i, iii, iv. 
elongation of the cells, iii. Diagrammatic transverse section in which a relatively shallow cortical 
zone has been affected, iv. The portion ab of iii, showing elongation of the cells with thickening. 
Note at A the local thickening in the bundle region, i, ii, and iiix 12 ; ivx 300. 
Here it will be seen that fully half the cortical parenchyma is affected, and 
that the wholesale elongation shows some very interesting features. The 
radial extension of the cells seems to have developed what may almost be 
termed ‘ lines of flow ’, some spreading fanwise from the vascular strands, 
others flowing round these obstructions (Fig. 3, ii). As is to be expected, 
these lines of flow come into contact in various parts of the petiole, this 
resulting in their mutual arrestment. Such contact regions are indicated 
by a separation line of gummy deposit of a yellow or brown colour 
(Fig. 3, iii and iv). Occasionally contact occurs between several lines of 
