78 THE OAK 
becoming russet-brown in colour. Young oaks retain 
their dead leaves till far into the winter, and-even old 
trees usually have some leaves attached till January. 
The young leaves secrete small quantities of sweet 
liquid on the superior face of the lamina, and are much 
visited by bees and wasps; this honey must come 
through the mem- 
brane. As the leaves 
approach maturity 
the lamina becomes 
bright and hard. 
The arrangement 
of the leaves is ex- 
pressed by the frac- 
tion 2, as already de- 
scribed, each node 
giving off one leaf at 
an open angle, the 
points of insertion 
being so arranged 
Fia. 21.—A portion of the ultimate that a line drawn 
ramifications of the vascular bundles, from the insertion of 
showing tracheids only, isolated from j 
the leaf by maceration. a given lower leaf, 
and joining it to the 
points of insertion of those above, passes twice round the 
twig before we arrive at the leaf situated vertically above 
the one started from, and this upper leaf is the sixth 
above. Although this is the commonest and normal 
arrangement, however, other dispositions are occasionally 
