40 
fully observed. It is not allowable to represent these 
matters, though small, at random, for each is some¬ 
what different from that which preceded it, and the 
differences may be characteristic of different species. 
§4. Take any common umbelliferous plant; it will 
probably be found that the base of the lowest leaf passes 
completely round the stem ; that the next is in the 
same condition; but that the one which follows does 
not surround the stem more than halfway; that the 
next scarcely surrounds it at all; and at last a scale 
is found fixed to the stem by only a slight point of 
attachment. Now, this gradual reduction of size and 
alteration of form, is characteristic of many plants, 
although it may not occur in others. It must be 
further rcmembei'ed that in a structure of this nature, 
as in leaves themselves, the most exact order is observed 
in the arrangement and placing of the several parts. 
It may happen that the flowei'-leaves now spoken of 
fall off when young, in which case scars will be left; 
as happens in the Ivy. The Ivy at one time bears 
flowei'-leaves similar to those observed in the sweet- 
scented Coltsfoot, but much smaller and more fu¬ 
gitive. They fall away early, leaving nothing but 
scars to indicate their existence. It would therefore 
be as great an ei'ror to represent the Ivy when in 
full flower, with the small flower-leaves upon it, as it 
would be to omit them in a case like that of Colts¬ 
foot. 
85. The branches on which these flowei'-leaves 
grow require to be represented in the same manner as 
the branches that bear common leaves; and what 
has been said already respecting the curves—the 
peculiar flat curves — which are observable in the con¬ 
figuration of branches at the places where the leaves 
