462 
The Progress of the 
[October, 
But the very same want of reference to definite colours 
and the same poverty of colour-terms may he traced in lite- 
rature very much later than the epoch of Homer. Thus 
Latin authors who flourished as late as the first century of 
the Christian era apply the word ccemleus to sky-blue, to 
steel-blue, to the colour of the human eyes, to the olive tree, 
and to dark grey and black objects ; viridis , commonly ren- 
dered green, is used by Virgil for the colour of the human 
face when turning pale, and by Pliny for the hue of the 
clear heavens ; purpureus is applied to the poppy, to the 
rainbow, to the violet, the rose, the willow, the human hair, 
the sea, and to the face when blushing. The colour of the 
sky is never mentioned in the Koran, and, according to 
Geiger, is first clearly alluded to in an Arabic work of the 
ninth century. 
Now, that the vision of man, and indeed of all animals, 
was at one time monochromatic, and has gradually reached 
its present stage of development by a passage through some 
of the phases of what we now call colour-blindness, — which 
must he regarded as a reversion to an earlier condition, — 
we feel no difficulty in admitting. But that the human 
colour-sense should remain in a condition so rudimentary 
down to the days of Homer, and even of Aristotle, Pliny, 
and Vitruvius, and should then advance by “ leaps and 
hounds ” to its present condition, is an assumption difficult 
to realise, and scarcely compatible with our modern evidence 
concerning the antiquity of our race. 
Mr. Wallace, with his usual acute insight, detedts an 
error in the conclusion to which Mr. Gladstone has been 
led. He remarks : — “ These curious fadts, however, cannot 
he held to prove so recent an origin for colour-sensations as 
they would at first sight appear to do, because we have seen 
that both flowers and fruit have become diversely coloured 
in adaptation to the visual powers of insedts, birds, and 
mammals. Red being a very common colour of ripe fruits 
which attract birds to devour them, and thus distribute 
their seeds, we may be sure that the contrast of red and 
green is to them very well marked. It is indeed just pos- 
sible that birds may have a more advanced development of 
the colour-sense than mammals, because the teeth of the 
latter commonly grind up and destroy the seeds of the larger 
fruits and nuts which they devour, and which are not usually 
coloured ; but the irritating effedt of bright colours on some 
of them does not support this view. It seems most pro- 
bable, therefore, that man’s perception of colour in the time 
of Homer was little, if any, inferior to what it is now, but 
