THE BIOLOGICAL ASPECT 311 
through intelligent adjustment or otherwise; that the part 
played by consciousness in the evolution of the higher and 
more active animals is apt to pass unnoticed or unrecorded. 
It is well, therefore, to put in a reminder that a great number 
of animals would never reach the adult state in which they 
pass into the hands of the comparative anatomist save for the 
acquisition of experience, and the effective use of the conscious- 
ness to which they are heirs ; that their survival is due, not 
only to their possession of certain structures and organs, but, 
every whit as much, to the practical use to which these posses- 
sions are put in the give and take of active life; and that 
many interesting problems which are keenly discussed by 
evolutionists in the light of natural selection presuppose 
conscious situations which are more or less tacitly taken for 
granted. 
Let us cast a rapid glance over some of these topics 
of biological discussion. The fascinating subject of mimicry, 
involving as it necessarily does the discussion of the value 
of warning colours and behaviour, a subject opening up an 
extensive group of problems so brilliantly studied by Professor 
Poulton, is meaningless save in so far as there is implied a 
conscious reaction to colour and form on the part of animals 
which can learn from experience. The warning colours re- 
instate a conscious situation, so that, misled by appearances, a 
bird mistakes the mimicking insect for its nauscous “ model.” 
The whole range of behaviour, included under play, 
experimentation, and practice, on the importance of which, 
following the lead so ably given by Professor Groos, we have 
insisted, is equally meaningless, save as a means to the acquisi- 
tion of serviceable experience for use in the more serious 
business of after-life; and experience is the establishment, 
through association and coalescence, of conscious situations 
which possess guiding value. And if, as we shall hereafter see, 
they may also be regarded as a means of securing pleasure, 
as a psychological end of behaviour, it is not less obvious that 
it is only through the development of consciousness that such 
a psychological end can have any existence. 
