
PITCHERS, STIPULES AND TENDRILS, 223 
vein ; it is simplest because though mature, it is organised, as 
all leaves are at an early period. 
That there is no distinction between a simple, digitate, 
pinnate, bipinnate leaf, except a degree of division. 
That the division depends upon the species, that it is inde- 
pendent of any veins. 
And hence all hypothetical ideas, that make the divisions of 
the leaves dependent on want of parenchyma between the 
veins, is erroneous. Rather the degree of length of the veins 
depends upon the form of the parenchyma. 
That as all leaves are simple ab initio, and the degree of 
composition being dependent on ulterior development, de- 
compound, or more than tripinnate leaves are the most ad- 
vanced. Hence the leaves should be taken into consideration 
in reference to the most perfect forms. 
Thus Bauhinia in leaf is the simplest perhaps of its section, 
those Bauhinie with emarginate leaves are simpler in this 
respect than those with bilobed, and these again than those 
with almost geminate leaves. 
It may not be amiss to observe that the form of leaf in 
Bauhinie in its early stages bears upon the subject of obli- 
quity of the style of the pistillum. A lamina well rounded 
off superiorly, will give an oblique style ; and if the rounding 
off is carried so far that the narrowed part of the lamina is at 
its base, we may have the ovarium of Boraginez or Labiate, 
at least in degree of obliquity.* 
A pinnated leaf is nothing but an entire leaf with the paren- 
chyma interrupted as far as the midrib. 
-This is shewn by development, the pinnules in the young 
state look like ovules in their young state, excrescences from 
the margins of the leaves; their development is from below 
upwards ; the lowermost being largish, while the uppermost 
are mere undulations. 
See Pl. 60. B. 8. Boswellia serrata. 
Those pinnules first developed, often so, continue fore- 
most, and become the largest. 
* See note p. 221. 

