to reveal, to the fullest possible advantage, the bright bars and 
splashes of colour which this extension alone can bring into being. 
Since these gaily coloured vestments seemed always to be 
associated with striking, stilted, attitudes, sometimes bordering 
on the grotesque, and always to be paraded in the presence of 
the female, Darwin drew the inference that they were the outcome 
of female choice persistently exercised during long generations. 
That is to say he held that, far back in the history of the race, 
these performers were soberly clad, as their mates commonly are. 
Then certain of the males of these now resplendent species began 
to develop patches of colour, small at first, but gradually increas- 
ing, generation by generation, in area and intensity. This 
progressive splendour, he believed, was due to the “ selective ” 
action of the females, which, from the very first, chose from among 
their suitors those who stood out among their fellows by reason 
of their brighter plumage. Thus the duller coloured males died 
without offspring. On this assumption each succeeding genera- 
tion would be, in some slight degree, brighter than the last, until 
the process of transformation ended in the glorified creatures we 
so admire to-day. 
It would be foreign to the purpose of this book to pursue this 
theme at length. Let it suffice to say that while the “ Sexual 
Selection ” theory still holds good, it has, so to speak, changed its 
complexion. And this largely owing to the accumulation of 
