- PART I.—STRUCTURAL. 11 
genitive of some proper name, and should always agree with the first 
name in gender. Thus, to take the genus Ranunculus again, we have 
the following specific names among others: repens (creeping), plebeius 
(common), parviflorus (small-flowered), lyallii (in honour of the late 
Dr. Lyall), and so on. 
1a. WHITE CLEMATIS. 
There are several species of Clematis found in New Zea- 
Jand: the most familiar one is the large-flowered white one— 
C, indivisa—which occurs commonly on the edges of the 
bush. Note its habit, and try to trace its stem to the ground. 
It is a shrub with a very tough climbing stem, which straggles 
over and through other shrubs and trees often to a great 
height. This climbing habit is in some respects perhaps dis- 
advantageous to the plant, as it renders it dependent on others 
for support; but this is more than counterbalanced by the 
small amount of tissue it requires to produce. Compare the 
thickness of its stem with that of the plant on which it grows, 
and you will find that the latter has had to develop far more 
dead tissue (for the most of the wood is merely dead support- 
ing-tissue) than the former. 
Observe the leaves. The petioles are somewhat long and 
curving, and come off in opposite pairs from each node; hence 
we say the leaf-arrangement of this plant is opposite. 
(Pl. L., fig. 2.) Hach petiole bears three blades or leaflets, but 
these leaflets differ very considerably from those of any of the 
buttercups examined. They vary in shape, but as a general 
rule are broad at the base and narrower at the apex, so as 
somewhate to resemble an egg in outline, and are therefore 
called ovate;* their margins are either entire (7.e., not 
cut into at all), or they are more or less marked with blunt 
notches or lobes. In consistence they are tough and leathery 
(=coriaceous}t), and their surface is glabrous and glossy, while 
through the blade the reticulation of the veins is easily made 
out. Now, if you examine a number of the petioles, particu- 
larly near the end of a branch, you will see how this plant 
climbs. Some of them are probably to be found bent or coiled 
into a spiral, and you may find that in tearing them off the 
tree or shrub on which they are growing you have brought 
away some bits of the branches round which they are coiled. 
When young these petioles are very sensitive to friction, and if 
they be gently rubbed they will slowly turn in the direction 
from whence the friction comes. This has been experimentally 
proved by Darwin and others. In its native state, when the 
young petioles of a plant are disturbed by the wind and are 
thus rubbed against adjacent twigs or branches they slowly 
* Tat. ovwin, an egg. + Lat. coriwm, leather. 
