by the purple stains everywhere visible within a short distance
of the bush."
These remarks suggest that the ivy adopts the converse attitude
towards its visitors to that forced upon the alpine flower. The
ivy bloom is small and inconspicuous, but then it has the season
to itself, and its inconspicuousness is no disadvantage, _i.e._
if one plant was more conspicuous than its neighbours, it would
not have any decided advantage where the pollinating insect is
abundant and otherwise unprovided for. Its dark-green berries in
spring, which I would describe as very inconspicuous, have a
similar advantage in relation to the necessities of bird life.
The experiments of M. C. Flahault must be noticed. This
naturalist grew seeds of coloured flowers which had ripened in
Paris, part in Upsala, and part in Paris; and seed which had
ripened in Upsala, part at Paris, and part at Upsala. The flowers
opening in the more northern city were in most cases the
brighter.[1] If this observation may be considered indisputable,
as appears to be the case, the question arises, Are we to regard
this as a direct effect of the more rigorous climate upon the
development of colouring matter on the blooms opening at Upsala?
If we suppose an affirmative answer, the theory of direct effect
by sun brightness must I think be abandoned. But I venture to
think that the explanation of the Upsala
[1] Quoted by De Varigny, _Experimental Evolution_, p. 56.
108
experiment is not to be found in direct climatic influence upon
the colour, but in causes which lie deeper, and involve some
factors deducible from biological theory.
The organism, as a result of the great facts of heredity and of
the survival of the fittest, is necessarily a system which
gathers experience with successive generations; and the principal
lesson ever being impressed upon it by external events is
economy. Its success depends upon the use it makes of its
opportunities for the reception of energy and the economy
attained in disposing of what is gained.
With regard to using the passing opportunity the entire seasonal
development of life is a manifestation of this attitude, and the
fleetness, agility, etc., of higher organisms are developments in
this direction. The higher vegetable organism is not locomotory,
save in the transferences of pollen and seed, for its food comes
to it, and the necessary relative motion between food and
organism is preserved in the quick motion of radiated energy from
the sun and the slower motion of the winds on the surface of the
earth. But, even so, the vegetable organism must stand ever ready
and waiting for its supplies. Its molecular parts must be ready
to seize the prey offered to it, somewhat as the waiting spider
the fly. Hence, the plant stands ready; and every cloud with
moving shadow crossing the fields handicaps the shaded to the
benefit of the unshaded plant in the adjoining field. The open
bloom
109
is a manifestation of the generally expectant attitude of the
plant, but in relation to reproduction.