320 Transactions. 



entire length. Prickles in small numbers on petiole and subpetiole, absent 

 from midrib. The distal end of the petiole is often swollen and bent, and 

 from it the leaflets project at varying angles so that they face the light. 



Both seedlings and adventitious shoots bear leaves which show all transi- 

 tions from simple to compound. The first leaf is simple, and is often 

 succeeded by a simple leaf with a lobe near its base. Later, leaves with 

 2 lobes may appear, and may be succeeded by a leaf with a lateral leaflet 

 in place of one of these lobes. From this stage to the adult 3-5-foliate 

 leaf there are numerous transitional forms. Injury to the growing-point 

 by frost or other means may lead to the development of lateral shoots, 

 which bear leaves in an order similar to that on the primary stem, and, on 

 lateral shoots from these, leaves may again develop in a corresponding order. 



(ii.) Leaj-anatomy . 



(a.) Shade Leaf. — Epidermis : Cells slightly flattened ; well-developed 

 cuticle ; stomata under surface only, level with epidermal cells. Hypoderm : 

 One layer isodiametrical cells, continuous on upper surface ; on lower 

 surface confined to the regions near the vascular bundles. Chlorenchyma : 

 Palisade — 2 layers, cells rather elongated. Spongy — 5-7 layers; cells 

 mostly elongated in direction of palisade, and so no sharp boundary be- 

 tween the tissues ; intercellular spaces fairly large. Vascular bundles : 

 Surrounded by sheath of coUenchyma, which connects with the upper and 

 the lower hypoderm ; a small band of stereome is present at the base of 

 the larger bundles. Leaf -margin : Very thick cuticle ; hypoderm 2 layers ; 

 chlorenchymatous cells elongated and arranged radially. Calcium oxalate : 

 AggTegate crystals. 



(6.) Sun Leaf. — Epidermis : Upper epidermis, cells with small lumina 

 and much-thickened walls ; cuticle very thick ; lower epidermis, walls 

 much thickened, but to a less extent than those of upper epidermis. 

 Chlorenchyma : Palisade — Cells very elongated and closely packed ; tissue 

 occupies almost one-half of leaf-thickness. Spongy — Cells fairly regular ; 

 intercellular spaces smaller than in shade leaf. Vascular bundle : Stereome 

 at base of each bundle well developed, and composed of cells with walls 

 greatly thickened. Leaf-margin : Hypoderm forms a mass of 3-4 layers 

 of cells with thick walls. 



(6.) Rubus schmidelioides. 



A. LIFE-FORM. 



In the shade of the forest this liane often grows to a height of 8 m. or 

 more before it reaches the sunlight. It may be growing upright beside 

 its support, or, if the support is a tree with smooth bark and few lateral 

 branches in the shade, the liane-stems may be coiled in a tangled mass at 

 the foot of the support, indicating that the liane has probably fallen down 

 through the increased weight of its own body. Between the liane's root and 

 the support there is often a distance of 4-5 m., and in this intervening space 

 the stem lies close along the ground, perhaps covered with debris. Also, 

 adventitious roots may be given ofi which anchor the stem, and doubtless 

 are of further use with regard to the food-supply. 



The stem, growing to 4 cm. in diameter, is dark brown in colour, and 

 smooth ; the nodes are 7-9 cm. apart, and usually sHghtly swollen. Prickles 

 are practically absent. From almost any portion adventitious shoots may 

 arise, which are characterized by very vigorous growth. Although very 



