IN TREWIA. 15 
Rubiacez, Rhizophorez and Dipterocarpex are simple 
leaves, acting as scales to the buds. 
Divisions of stipules. 
Spurious stipules, mere processes of the petiole, as Rosa- 
cee ; ochresz, stipulets of Leguminose. 
True ditto, having a distinct connection with the axis, on a 
different plane from the leaf or leaves, and performing the 
functions of scale-buds. Bucklandii, Rubiacez. 
Intermediate connection with the axis very rudimentary, 
no function, Euphorbiacez, Rhamnez. 
In conformity with these definitions botanists have boni 
singularly consistent in considering all stipulae to be double 
organs, although they may present no trace of composition, 
and although the line of insertion may be upon a plane 
above that of the leaves to which they are referred. The 
same supposition of their being always double organs, and 
consequently always having a numerical relation with their 
leaves, afforded ground for Mr. Lindley, to question the 
nature of the so-called stipule,—a question disputed by Mr. 
Bentham, who seems inclined to be of opinion that the 
‘number of parts forming stipule may have. an increased 
numerical relation with their leaves. 
In the latest works, such as that of Adr. Jussieu, the 
stipule are considered as forming part of the leaf. 
The study of development however, which appears to be 
the most accurate way of ascertaining the nature or degree of 
composition of organs, appears to me to warrant the sup- 
position of stipulae belonging to leaves, and being double 
organs in a comparatively small number of cases only. 
It appears to me that the advocates of the stipuline nature 
of parts of the whorls of Stellate will have considerable 
difficulty in explaining such instances as Rubia cordifolia, 
in which the parts of the whorl are 4, all petioled, and if 
these are leaves the others are so exactly alike in develop- 
ment, etc. as to be leaves also. íi 
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