find that a careful perusal of the _Descent of Man_ reveals the presence
in Darwin's mind of two quite distinct theories, neither of them fully
developed, as to the psychological meaning of the facts he was collecting.
The two following groups of extracts will serve to show this very
conclusively: "The lower animals have a sense of beauty," he declares,
"powers of discrimination and taste on the part of the female" (p.
211[21]); "the females habitually or occasionally prefer the more
beautiful males," "there is little improbability in the females of insects
appreciating beauty in form or color" (p. 329); he speaks of birds as the
most "esthetic" of all animals excepting man, and adds that they have
"nearly the same taste for the beautiful as we have" (p. 359); he remarks
that a change of any kind in the structure or color of the male bird
"appears to have been admired by the female" (p. 385). He speaks of the
female Argus pheasant as possessing "this almost human degree of taste."
Birds, again, "seem to have some taste for the beautiful both in color and
sound," and "we ought not to feel too sure that the female does not attend
to each detail of beauty" (p. 421). Novelty, he says, is "admired by birds
for its own sake" (p. 495). "Birds have fine powers of discrimination and
in some few instances it can be shown that they have a taste for the
beautiful" (p. 496). The "esthetic capacity" of female animals has been
advanced by exercise just as our own taste has improved (p. 616). On the
other hand, we find running throughout the book quite another idea. Of
cicadas he tells us that it is probable that, "like female birds, they are
excited or allured by the male with the most attractive voice" (p. 282);
and, coming to _Locustidæ_, he states that "all observers agree that the
sounds serve either to call or excite the mute females" (p. 283). Of birds
he says, "I am led to believe that the females prefer or are most excited
by the more brilliant males" (p. 316). Among birds also the males
"endeavor to charm or excite their mates by love-notes," etc., and "the
females are excited by certain males, and thus unconsciously prefer them"