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produce much mucilage. The leaf teeth have two shapes; between 
the larger egg-shaped ones, rounded in front, there are smaller teeth 
turned more inwards. 
As Reinke already observed a lateral vein of the leaf terminates 
in every leaftooth, just below its apex; above this there are some 
stomata. The secretion of mucilage takes place from the epidermis, 
the cells of which contain mucilage; the epidermis contains in addition 
larger cells, completely filled with mucilage. These inucilage-cells 
are also found in the sub-epidermal layer of the tissue. Often their 
number is so large, that as a result the leaftooth shows numerous 
transparent spots. 
But besides the Secretion of mucilage by the numerous teeth and 
glands of the leaf surface, there is also a secretion by the stipules 
and especially by those which are placed higher on the axis. These 
are covered on their inner sides with very numerous glands of the 
same shape as those which occur on the leaves, and they too bear 
numerous large mucilage-cells in their epidermis. 
The youngest leaves and stipules are covered with a thick layer 
of mucilage. 
In the moist space under the bell-jar the outermost leaves were 
already completely covered with fluid next morning. This fluid 
consisted of water or very watery mucilage and had evidently been 
secreted from the glands of the leaf surface, which, although originally 
mucilage-glands, afterwards behave as water-glands. 
At that time there was no proper formation of drops, but some 
hours later it could be observed at the apex and the teeth. 
Sambucus nigra. 
The young leafteeth are completely hidden, because the leaves 
are rolled up very closely in the bud; they lie against the lea 
surface and curve upwards. The secretion by the leafteeth is limite 
to the extreme apex, which resembles that of Kerria japonica. In 
the youngest bud-stages there is here a secretion of mucilage. 
In addition the leaf surface is closely covered on its inside an 
outside with strongly secreting club-shaped trichomes, the shape, 
development and mucilage-secretion of which have already ^ een 
described in detail by Hanstein (1. c. p. 731). 
In the experiment with a cut branch under a bell-jar a ne 
formation of drops is soon observed at the apices of the young leaves^ 
Further it becomes evident on unrolling the leaves, that the inner 
space itj, tilled with water, while numerous drops of water are a s 
found on the outside. The latter fluid is certainly derived from 
