it only required five
minutes. After the third trial, the routes became more direct, there was
less aimless wandering. The time of the twentieth trial was forty-five
seconds; that of the thirtieth, forty seconds. In the thirtieth case,
the path followed was quite direct, and so it was on the fiftieth trip,
which only required thirty-five seconds. Of course, the whole thing did
not amount to very much; but there was a definite learning, _a learning
from experience_, which has played an important part in the evolution of
animal behaviour.

Comparing reptiles with amphibians, we may recognise an increased
masterliness of behaviour and a hint of greater plasticity. The records
of observers who have made pets of reptiles suggest that the life of
feeling or emotion is growing stronger, and so do stories, if they can
be accepted, which suggest the beginning of conjugal affection.

The error must be guarded against of interpreting in terms of
intelligence what is merely the outcome of long-continued structure
adaptation. When the limbless lizard called the Slow-worm is suddenly
seized by the tail, it escapes by surrendering the appendage, which
breaks across a preformed weak plane. But this is a reflex action, not a
reflective one. It is comparable to our sudden withdrawal of our finger
from a very hot cinder. The Egg-eating African snake Dasypeltis gets the
egg of a bird into its gullet unbroken, and cuts the shell against
downward-projecting sharp points of the vertebrae. None of the precious
contents is lost and the broken "empties" are returned. It is admirable,
indeed unsurpassable; but it is not intelligent.

Sec. 5

Mind in Birds

Sight and hearing are highly developed in birds, and the senses, besides
pulling the triggers of inborn efficiencies, supply the raw materials
for intelligence. There is some truth, though not the whole truth, in
the old philosophical dictum, that there is nothing in the intellect
which was not previously in the senses. Many people have admired the
certainty and alacrity with which gulls pick up a fragment of biscuit
from the white wake of a steamer, and the incident is characteristic. In
their power of rapidly altering the focus of the eye, birds are
unsurpassed.

To the sense of sight in birds, the sense of hearing comes a good
second. A twig breaks under our feet, and out sounds the danger-call of
the bird we were trying to watch. Many young birds, like partridges,
respond when tw