alternately push with their forefeet against the mammary glands of
their mothers, to excite a freer secretion of milk, or to make it flow.
Now it is very common with young cats, and not at all rare with old
cats of the common and Persian breeds (believed by some naturalists to
be specifically extinct), when comfortably lying on a warm shawl or
other soft substance, to pound it quietly and alternately with their
fore-feet; their toes being spread out and claws slightly protruded,
precisely as when sucking their mother. That it is the same movement is
clearly shown by their often at the same time taking a bit of the shawl
into their mouths and sucking it; generally closing their eyes and
purring from delight. This curious movement is commonly excited only in
association with the sensation of a warm soft surface; but I have seen
an old cat, when pleased by having its back scratched, pounding the air
with its feet in the same manner; so that this action has almost become
the expression of a pleasurable sensation.
Having referred to the act of sucking, I may add that this complex
movement, as well as the alternate protrusion of the fore-feet, are
reflex actions; for they are performed if a finger moistened with milk
is placed in the mouth of a puppy, the front part of whose brain has
been removed.[117] It has recently been stated in France, that the
action of sucking is excited solely through the sense of smell, so that
if the olfactory nerves of a puppy are destroyed, it never sucks. In
like manner the wonderful power which a chicken possesses only a few
hours after being hatched, of picking up small particles of food, seems
to be started into action through the sense of hearing; for with
chickens hatched by artificial heat, a good observer found that making
a noise with the finger-nail against a board, in imitation of the
hen-mother, first taught them to peck at their meat. [118]
I will give only one other instance of an habitual and purposeless
movement. The Sheldrake (_Tadorna_) feeds on the sands left uncovered
by the tide, and when a worm-cast is discovered, it begins patting the
ground with its feet, dancing as it were, over the hole; and this
makes the worm come to the surface. Now Mr. St. John says, that when
his tame Sheldrakes came to ask for food, they patted the ground in an
impatient and rapid manner. [119] This therefore may almost be
considered as their expression of hunger. Mr. Bartlett informs me that
the Flamingo and the Kagu (_Rhinochetus jubatus_) when anxious to be
fed, beat the ground with their feet in the same odd manner. So again
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