344 Transactions. 



of a single seedling, but, of course, moving through a larger circle, and 

 thus giving a better chance of touching a support. This tendency to twine 

 round one another is not confined to the movements of any two individuals 

 only, for very often large numbers are seen thus giving mutual support — 

 in some cases as many as 15. These then form a rope-like mass, whose 

 resistance to bending is very effective ; and the resistance is further aided 

 by the positions of the roots of the individuals, they being arranged round 

 the ascending shoots in a circle, whose radius may be as much as 10 cm. 

 By such means the seedlings often attain a height of fully 1 m. — ^a height 

 at which the vegetation available as support is usually very abundant. 

 There is no doubt that the leaf is of importance as an aid to climbing. The 

 most common leaf-form of the seedling is the linear form. The leaves are 

 borne in pairs, and project at right angles from the stem to a distance of 

 6 cm., and by torsion of the stem they point in all directions. There is thus 

 a probability that any one of these leaves may touch a support., and by 

 resistance to bending allow the seedling to reach a greater height. From 

 any portion of a shoot which is bending over towards the ground, lateral 

 shoots may arise for fully 40 cm., and, as the primary shoot at the place 

 of origin of these lateral shoots may be anything up to 20 cm. from the 

 ground, a comparatively high position is reached. 



7. Clematis indivisa. 



The seedlings of this species are not widespread in the forest, being 

 •confined chiefly to a small part near one of the few adult female 

 plants. There they are well sheltered, and are surrounded by numerous 

 supports. 



Without any support they can stand erect for 40 cm. The leaves, which 

 a,re decussate, are at the lowest nodes simple, and project from the stem 

 for 5-6 cm. They are thus of assistance in lessening vertical strains on 

 the seedling. The third pair of leaves usually have petioles which upon 

 continued contact with an object bend slightly. The}* can thus over- 

 come any slight lateral strain, and, as any two consecutive pairs of leaves 

 will operate at right angles to each other, they assist in maintaining the 

 seedling in an erect position and enabling it to reach a greater height. 

 The petioles of leaves succeeding the third pair are more sensitive, and 

 encircle anv small branch which they touch ; in doing this they become 

 much thickened and strengthened. When a pair of leaves arise from a 

 stem they at first project beyond the growing-point. The leaf-blades for 

 a long time remain small, but the petioles elongate to a length of 2-3 cm. 

 The leaves then gradually bend down until they project straight out from 

 the stem, and if in this downward movement they touch any branch they 

 entwine it. As the leaf-blades at this stage are still smaU, their size does 

 not retard the action of the petioles by their becoming arrested in the 

 encircling movement, but they later expand, as do also the blades of leaves 

 which have reached no support in the downward curvature. Above the 

 anchorage secured by any of the petioles the free end portion of the seed- 

 ling can rise erect for fully 30 cm., and so, on account of the numerous 

 supports which usually surround the seedlings, the latter easily make their 

 way into the sunlight. 



However, should a seedling reach no support, and thus bend down, any 

 lateral shoot from the primary axis will rise up in a position perhaps 20 cm. 

 from the former position of seedling, and so reach a support. 



