days did not cause the destruction of the starch-granules. On the other
hand, the immersion of fresh lime and cherry leaves for eighteen hours in
artificial pancreatic fluid, led to the dissolution of the
starch-granules in the guard-cells as well as in the other cells.
From the secretion with which the leaves are moistened being alkaline,
and from its acting both on the starch-granules and on the protoplasmic
contents of the cells, we may infer that it resembles in nature not
saliva, {40} but pancreatic secretion; and we know from Fredericq that a
secretion of this kind is found in the intestines of worms. As the
leaves which are dragged into the burrows are often dry and shrivelled,
it is indispensable for their disintegration by the unarmed mouths of
worms that they should first be moistened and softened; and fresh leaves,
however soft and tender they may be, are similarly treated, probably from
habit. The result is that they are partially digested before they are
taken into the alimentary canal. I am not aware of any other case of
extra-stomachal digestion having been recorded. The boa-constrictor is
said to bathe its prey with saliva, but this is doubtful; and it is done
solely for the sake of lubricating its prey. Perhaps the nearest analogy
may be found in such plants as Drosera and Dion a; for here animal matter
is digested and converted into peptone not within a stomach, but on the
surfaces of the leaves.
_Calciferous Glands_. These glands (see Fig. 1), judging from their size
and from their rich supply of blood-vessels, must be of much importance
to the animal. But almost as many theories have been advanced on their
use as there have been observers. They consist of three pairs, which in
the common earth-worm debouch into the alimentary canal in advance of the
gizzard, but posteriorly to it in Uroch ta and some other genera. {41a}
The two posterior pairs are formed by lamell , which, according to
Claparede, are diverticula from the sophagus. {41b} These lamell are
coated with a pulpy cellular layer, with the outer cells lying free in
infinite numbers. If one of these glands is punctured and squeezed, a
quantity of white pulpy matter exudes, consisting of these free cells.
They are minute, and vary in diameter from 2 to 6 _ _. They contain in
their centres a little excessively fine granular matter; but they look so
like oil globules that Claparede and others at first treated them with
ether. This produces no effect; but they are quickly dissolved with
effervescence in acetic acid, and when oxalate of ammonia is added to the
solution a white precipitate is thrown down. We may therefore conclude
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