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snap-dragon. But no sooner does the corolla fall than
the peduncle begins to curve inwards to the wall and
usually contrives to tuck its seed vessels well into the
brick-work again.
As an illustration of migration, we may take the
Selaginella convoluta, which is found in the arid deserts
of Central America. “ In the dry season, when every
particle of moisture is extracted from the soil, it is
detached from its growing place, rolled up into a ball,
and carried away by the violent equinoctial gales which
prevail at the time in those regions—often to very great
distances. It remains coiled up in this form for a
considerable time, but if carried to a marsh or the
margin of a stream, or any other moist place, it begins
slowly to unfold itself and spread itself out flatly on the
soil, assumes its former vigour and freshness, takes fresh
root, developes its fructification and casts abroad its
seed upon the air. When this new situation is dried up
it resumes its old unsettled habits and, like an adventurous
pilgrim, takes advantage of the wind to emigrate to a
more favourable locality.”
Now if these actions are the outcome of intelligence as
much as the actions of animals, then the arguments already
adduced will suffice to exclude the action of Natural
Selection, seeing that intelligent adaptation will anticipate
the slower process of Natural Selection. But if they are
physical habits, without any mental element in them what
ever, the problem of instinct does not arise, for by universal
consent it does involve the presence of a mental element.
To revert once more to the lowest form of animal life.
We may suppose, for the sake of argument, that the
actions of the simplest organisms are illustrations of reflex
action, which have had their origin in the mutual inter
action of the organism and its conditions. If there is any