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I. Secretion of water in leaves. 
Kerria japonica. 
The leaf-apex and the teeth of the leaf-margin are acuminate and 
lanceolate. The vein running into the tooth ends at some distance 
from the apex; above this there are a number of water-pores 
resembling stomata. 
The portion of the leaf-tooth above the termination of the vascular 
bundle, where in other plants there is a so-called epithemal tissue 
of peculiar structure which has more or less the properties of spongy 
parenchyma, consists in Kerria japonica of a mucilage-gland of 
which both the epidermal and the interior cells are rounded and 
tilled with. highly refractive substances. The secretion of mucilage 
occurs in young-leaves in the bud; it takes place with elevation of 
the cuticle. 
Similar glands but somewhat larger and more rounded are also 
•found at the apex and margin of the young stipules and especially 
also at the edge of the calyx-segments; they differ from the glands 
of the leaf-margin in shape and in size, but the cells of which they 
are composed have the same highly refractive contents. 
It a cut branch of this plant is placed in a moist space a 
formation of drops soon takes place at the apex and the teeth 
of the young leaves, as was mentioned above. The drops secreted 
from the same cells which formerly, in the bud, secreted mucilage, 
contain no mucilage or at most very little. If these drops are 
removed with a strip of blotting-paper, new drops soon make their 
appearance. 
The same phenomenon occurs in the young flowerbud. The water 
is secreted in the form cf droplets which flow together to a few 
large drops. There can be no question of a secretion of water by 
means of an epithema. It must undoubtedly depend on the endos- 
motic activity of the gland-cells which with great force draw water 
from the surrounding tissues and from the vascular bundle and 
Philadelphia coronarius. 
In the second half of April when the buds began to open, a cut 
branch was placed in a glass of water under a glass bell-jar which 
was kept moist. 
The outermost leaves of the bud, which before had thSir margins 
adjoining, began to separate. The next pair of leaves, placed alter¬ 
nately, thus became visible; of this pair the margins still adhered. 
The remaining leaf-pairs \yere still enclosed. 
