10 NoTEs ON WINTER BOTANY. 
for action in time of battle. The whole process by which leaves, 
useless twigs, and all sorts of herbaceous material is broken up 
and overcome before the next spring’s vigorous growth begins, is 
of extraordinary interest. The formation of cork and the leaf 
fall are well known, but the destruction of all those many her- 
baceous stems that last but for one season is not so well under- 
stood. Perhaps the most remarkable point about them is the 
way in which they survive, often until well on in winter time, just 
indeed so long as the dead, dry, withered, and yet elastic, stalk 
can be of use in disseminating the fruits and seeds. When the 
last spore is shed the destruction of the stalk soon follows. 
Herbaceous stems consist generally of a ring of woody or 
collenchymatous mechanical tissue, often raised into ribs or 
flanges. Outside this there are, successively, first soft 
parenchyma, and then the tough, more or less thickened 
epidermis. So soon as the last seeds are definitely formed and 
separated from the wall of the ovary, the drying of the stalk 
begins (probably the water is no longer assisted in ascending 
the stem by the demands of the ripening seeds). Then, as the 
cells in the upper part of the stalk gradually die, less and less. 
water ascends until they become like those of dried herbarium 
specimens which may last 100 years or more if kept thoroughly 
dry and free from certain insects. 
But the lower part of the stalk just above the ground is kept 
generally more or less moist by surrounding vegetation: in 
Umbelliferze also the part just above the node is kept fresh and 
humid by the remains of the vagina; similar sheathing leaf bases. 
or stipules have the same effect in other plants. 
It is at these spots that the first fungus attack usually begins. 
They remind one of the decay of an ordinary paling stob, which 
usually sets in at the neck. That part of the stob which is in air 
may be quite sound* and also the basal end planted in the earth, 
but just at or near the surface of the ground, where the condi- 
tions frequently change from moist to dry, fungus attacks are 
favoured and the stob rots through. 
*The gates of Constantinople destroyed by the Turks in 1453 when 
eleven centuries old of Cypress (C. sempervirens) in air and the wood 
of Juniperus oxycedrus, buried in the earth in Malta, were quite sound 
after respectively 1100 years and 400 years.—Boulger ‘* Wood,” 1902. 
