had thus been drawn in. We may
perhaps account for the fact of a still larger proportion of the
laburnum leaves not having been drawn in by the base, by worms
having acquired the habit of generally drawing in leaves by their
tips and thus avoiding the foot-stalk. For the basal margin of the
blade in many kinds of leaves forms a large angle with the foot-
stalk; and if such a leaf were drawn in by the foot-stalk, the
basal margin would come abruptly into contact with the ground on
each side of the burrow, and would render the drawing in of the
leaf very difficult.
Nevertheless worms break through their habit of avoiding the foot-
stalk, if this part offers them the most convenient means for
drawing leaves into their burrows. The leaves of the endless
hybridised varieties of the Rhododendron vary much in shape; some
are narrowest towards the base and others towards the apex. After
they have fallen off, the blade on each side of the midrib often
becomes curled up while drying, sometimes along the whole length,
sometimes chiefly at the base, sometimes towards the apex. Out of
28 fallen leaves on one bed of peat in my garden, no less than 23
were narrower in the basal quarter than in the terminal quarter of
their length; and this narrowness was chiefly due to the curling in
of the margins.
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