The Sleeping of the Fields 367 
bricks do in a house-wall, pressed closely together 
in horizontal rows (Fig. 99@). Sometimes they con- 
tain a brownish, granular 
substance, but oftener they (FES 
are, in the expressive phrase em 
once used by a daughter of CA 
Erin, ‘‘ full of emptiness,’ CAA 
and in this case they may be CS 
much bent and crinkled. Fic. 994.—Cork cells. 
The cork layer which © chestnutmuch magniied) 
severs the leaf from the bough does its work 
gently. At first it is not an unbroken sheet of 
cells, but a thin, incomplete, and porous plate, 
which intersects the softer tissues of the leaf-stalk 
but does not cut across the bundles of fibres and 
vessels which are the vital connection between 
bough and leaf. 
At about the same time, or a little later in the 
season, another change takes place in the tissues of 
the leaf-stem. Now just outside the forming cork- 
plate there is a narrow band of rounded cells, which 
lie loosely together with many empty spaces among 
them. This is the ‘‘absciss’’ or ‘‘cutting-off’’ layer, 
and just here the stem-tissue is very easily ruptured. 
By October the corky scale at the base of each 
leaf-stalk has gained its full thickness, and severs 
