Bird. — Lianes of the Ancient Forest of Ganterhury Plains. 321 



slender, the stems may grow erect without support to a height of 1 m. or 

 more, further growth resulting in the shoot bending over and finally touch- 

 ing the ground. Here they continue their rapid growth, and bear leaves, 

 which stand upright with their expanded laminae facing the incident rays 

 of light. As adventitious shoots frequently arise high up on the plant, 

 they are important in reaching the new positions of support, either on the 

 same tree or on adjacent trees. Lateral branches normally arise where 

 the stem is growing in the sun. They are at first usually at right angles 

 to the main axis, but upon reaching the branches of the support grow up- 

 wards and give rise to more shoots. At other times, failing to come into 

 contact with a support, they hang down, forming with other branches a 

 divaricating reticulation, upon which masses of leaves are borne. The 

 divisions of the leaves assist further in the formation of a " leaf-mosaic," 

 whose efhciency may be judged by the manner in which the supporting 

 tree is often hidden from sight. 



In the more exposed portions of the forest the species scrambles over 

 low-lying shrubs, forming a dense mass, with interlacing branches, which 

 have a tendency to droop, and thus often hide the support. 



B. LEAP. 



(i.) Leaj-form. 



Leaves 3-5-foliate ; leaflets 4-5-5 cm. long, orbicular-ovate or orbicular- 

 oblong, coriaceous, acute, rounded or cordate at base, irregularly toothed, 

 usually pubescent beneath. Petioles 4-6-5 cm. long ; subpetioles vary in 

 length, terminal 4— 5-5 cm. long, basal 0-5-1 cm. long. Prickles numerous 

 on petioles and less numerous on subpetioles, usually absent from midrib. 



Shade leaves : Adult, subcoriaceous ; juvenile, membranous, and often 

 brightly pigmented, being reddish-brown in colour. 



(ii.) Leaf -anatomy . 



(a.) Sun Leaf. — Epidermis : Both upper and lower epidermis have a 

 well-developed cuticle, the upper being especially thick ; stomata on lower 

 surface only, and level with the epidermal cells. Hypodermis : A single 

 layer of large cells with collenchymatous walls inside both upper and lower 

 epidermis. Chlorenchyma : Palisade tissue — 2-3 layers of elongated cells, 

 rather loosely packed. Pneumatic tissue — 6-8 layers of irregular cells, 

 more or less rounded ; intercellular spaces very large. Vascular bundles : 

 Collateral, surrounded by a well-developed sheath of thick-walled paren- 

 chyma, the cells below the vascular bundle having their walls especially 

 thick. Leaf-margin is strengthened by 2-3 layers of collenchyma, which 

 extend for a few cells' length along both surfaces. Crystals of calcium 

 oxalate are present in the hypoderm and the chlorenchyma in the form of 

 aggregate crystals. 



(b.) Shade Leaves. — Shade leaves have most characteristics in common 

 with exposed leaves. The variations are — (1) Many cells of the hypoderm 

 have chloroplasts ; (2) cuticle is not so well developed ; (3) less strengthen- 

 ing of the leaf-margin ; (4) pigment may be present. The cells of the upper 

 hypodermis and the first row of palisade cells often contain abundant 

 anthocyan, which is scattered to a less extent throughout the rest of the 

 chlorenchyma. 

 11— Trans. 



