142 BOTANY 
In the coprosma the margin is entire and in the 
tupari it is serrate. In the oak the indentations are 
much deeper and the leaf is pinnatifid (L. findo fidi, I 
cut), while in the poppy and sow-thistle, being deeper: 
still, they produce a pinnatisect (L. sectus, cut) blade. 
The last step is seen in the leaves of the bean, wistaria,. 
kowhai and clianthus, where the indentations reach 
the midrib, and the leaf is pinnately compound. 
In following the palmate type (Fig. 101), we 
have the margin entire in the kidney fern and kawa-- 
kawa, and dentate in the whau. In the fig, the 
deeper indentations give a palmatifid leaf, while in 
the passion flower, being deeper still, they produce the: 
type termed palmatisect. Finally, in the _ horse-. 
chestnut, panax and pate (Schefflera digitata) the 
divisions meet at the base of the midrib and the leaves: 
become palmately compound. 
It has been noted that, as a rule, leaves which, like: 
the tobacco, sunflower and rangiora can raise them- 
selves freely to the sun and air, are broad, flat and 
horizontal; but; in crowded situations, as a hedge 
or grassy meadow, where leaves are competing: 
with one another for the sunlight, special forms: 
have been developed suited to the particular: 
environment. In the struggle for existence, the: 
fittest have. survived and the less fit have gone 
to the wall. In meadows, where the 2Tasses: 
are densely crowded, the leaves are narrow and crow 
upwards to the light without the delay that would 
arise from the production of a broad blade, for the 
development of which there would be insufficient room. 
In hedges, and in the shade of the forest, the leaves: 
are generally much divided, as we see in vetches and’ 
cleavers and the great variety of ferns that clothe 
the forest floor. The leaflets of their compound blades: 
wave freely in the air, forming a kind of network to: 
arrest such carbon dioxide as may be present in the: 
