BiuD. — Lianes of the Ancient Forest of Canterbury Plains. 345 



In many cases seedlings are found tvhich, in addition to their petiole-action, 

 ascend a support hy twining, the ttvining being in all cases sinistrorse. The 

 petioles entirely surround the support, one of each pair circling to the right 

 and the other to the left, and they thus firmly grasp the support. 



8. Tetrapathaea australis. 



The seedlings are found chiefly in the exterior portions of the forest, 

 where the vegetation is dense, and thus they are surrounded by numerous 

 supports of varying nature. Without any support the seedling can stand 

 erect for 40 cm., but a greater height can be reached near any support by 

 means of the leaves. These are borne alternately, and project straight out 

 from the stem for 6-8 cm. ; and, being fairly rigid, they support the seed- 

 ling, and maintain it in its erect position. But most assistance is gained 

 from the tendrils which arise while the seedling is still standing erect, 

 usually appearing first from about the 18th node. They at first project 

 bevond the growing-point, with tip bent outwards, this bending, no doubt, 

 assisting the tendrils to retain their hold upon any object with which they 

 come into contact. These tendrils do not remain in this projecting position, 

 but gradually bend down until they lie along the stem of the seedling, with 

 the apex pointing towards the ground. And in this downward bend- 

 ing they may come into contact with a support. The support is firmly 

 encircled, and by spiral contraction of the tendril the seedling is pulled 

 towards the support. Having thus obtained an anchorage, the seedUng 

 may rise up from this point to a still greater height, and in so doing may 

 obtain further support. Should the young seedling reach no support, it 

 bends over to the ground, and grows for a while horizontally. In this way 

 it may reach a support; and, further, any lateral shoots springing from 

 the primary shoot, and rising up as they do for fully 30 cm., increase the 

 chances of the seedling coming into contact with some shrub or other sup- 

 port. From the lowest branches of the shrubs the growth of the liane to 

 the top of the shrub is easy, and thence the liane has little difficulty in 

 reaching higher adjacent plants, and thus rising to the sunlight. 



IV. THE EVOLUTION OF LIANES. 

 The question of the evolution of lianes cannot be gone into in much 

 detail, for this would entail a close acquaintance with all the New Zealand 

 lianes and with various classes of forest. However, the lianes present in 

 the forest investigated exhibit an interesting series from non-specialized 

 to highly specialized forms. 



1. Scramblers. 



Characteristics common to all the classes of lianes are the great elonga- 

 tion of stem and the absence of lateral branches. Now, it must be noted 

 that in positions in the forest-interior where the liane-stems, attenuated and 

 imbranched, elongate rapidly, this elongation is characteristic also of other 

 plants, certain species of Coprosma — bushy shrubs as distinct from lianes 

 as possible — being most noticeable in this regard.* From such observations 



* Subsequent to the writing of this, Dr. L. Cockayne has drawn the writer's attention 

 to the fact that in certain parts of the forest near Wellington stems of Coprosma 

 robusta, norinaliy a bushy shrub, are so greatly elongated that without careful attention 

 thr3y are easily mistaken for true liane-stems. 



