with
a young male.[93] Even among species noted for their conjugal fidelity
this sometimes happens. Female pigeons, for example, have been known
to fall violently in love with strange males, and this is especially
common if the legitimate spouse is wounded or becomes weak.[94] Darwin
records a very curious case of a sudden passion appearing in a female
wild-duck, who, after breeding with her own mallard for a couple of
seasons, deserted him for a stranger--a male pintail.

"It was evidently a case of love at first sight, for she swam
about the newcomer caressingly, though he appeared evidently
alarmed and averse to her overtures of affection. From that hour
she forgot her old partner. Winter passed by, and the next
spring the pintail seemed to have become a convert to her
blandishments, for they nested and produced seven or eight young
ones."[95]

I am tempted to wait to consider the immense significance of such
cases as these in the analogy they bear to our own sudden preferences
in love. The question as to the moral conduct of this duck opens up
suggestions of those cases of exceptional love-passions, which all our
existing institutions, laws and penalties have never been able to
crush. The desire for sexual variety is the ultimate cause of all
sexual lapses and irrationalities. It is a mistake to think that this
is a condition peculiar to mankind and the result of civilisation. If
this were so it would be easier to deal with; but before these
deeply-rooted instincts of sexual hunger we are often powerless. I
know of no question that needs to be faced by women more than this
one. I would like to say more about it. But already this first section
of my book has exceeded its limits. I must, therefore, pass on, to
draw attention to the fact, clearly proved by the case of this
wild-duck's love, as well as by many other examples, that it is the
females, who, exercising their right of selection much more than the
males, introduce individual preference into their sexual
relationships. The difficulty is that such preference, of profound
biological importance, is often thwarted among civilised people by
considerations of property and the accepted morality. From this
standpoint permanent marriage may often fail to do justice to the
sexual needs both of the individual and the wider needs of the race.
Nature has no care for sex-morals as we understand them, any mode of
sexual union is equally right