Oldal 177 [177]
COLOURS IN RIPPLED WATER 111
of purple? The fact that the resulting colour appears to be
independent of the colour of the seaweed and to arise from
any dark bottom, would point to its being also an effect of
contrast. Moreover the pinkish colour seems to be more
noticeable when looking obliquely, so that one is inclined to
put it down, as in the case of the cloud shadows, to the sur¬
face-reflected light becoming tinged with the complement¬
ary of the surrounding colour. But there is much to be
said on both sides of this difficult and complicated question.