THEIR FORMS AND FUNCTIONS. 517 
the axil of one of these leaves. Thus the young and tender 
growth is amply protected. 
Aristolochia elegans, Mast., while really exstipulate, has a 
small, cordate, membranous, subsessile leaf in the axil, which 
resembles a single intrapetiolar stipule or even a pair. Close 
examination shows that this stipule-like process is really the 
first leaf of an axillary axis or bud. It clasps the main axis 
with its auricles, and has two buds in different stages of advance- 
ment lying between it and the petiole of the leaf in whose axil 
it occurs. The small leaf belongs to the larger and more 
advanced bud. 
On examination of the terminal bud of the main axis, the 
axillary buds, especially one of them, are seen to be already in an 
advanced state. The stipule-like leaf is conduplicate over the 
larger bud, but being much wider than the latter even when 
folded, its margins become involute, so that the bud is subulate 
in outline. The stipule-like process has therefore been developed 
for the protection of the larger and most advanced axillary bud, 
which it completely covers. 
The terminal bud, consisting as it does of numerous leaves in 
an advanced state, is protected by its own leaves, the older 
protecting the younger. All the leaves on the main axis are 
conduplicate, folding one inside the other successively, with the 
two halves and their edges perfectly flat, not involute, as in the 
case of the stipule-like leaf when in bud. 
PIPERACER. 
In Piper longum, Linn, var. sarmentosum, the leaves are alter- 
nate, petiolate, stipulate, rotund, cordate, acuminate, or rather 
cuspidate, 5-7-nerved with incurved nerves, and persistent, 
involute from the edges to the midrib in bud, forming a cylindrical 
mass ; the petiole is semiterete, grooved above, but more deeply so 
inside the stipules. 
The stipules are 9-15 mm. long, adnate to the lower half of 
the petiole, converging towards the apex and free at the tips, 
strongly overlapping by their free edges, adnate by their base all 
round the axis, becoming brown and disarticulate from the petiole 
atter the leaf is fully developed. In all these respects they 
closely resemble those of Magnolia, except that their posterior 
edges are free and much imbricated, but not connate. 
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