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, {22} 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 Dionaea; 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 Urochaeta and some other genera. {23} The two posterior pairs