COURTSHIP 261 
behaviour unquestionably is determined by such influence 
in the serious business of courtship. And then the further 
question arises—Is it a matter of indifference what the appear- 
ance and behaviour of the individual of the opposite sex may 
be? AreA., B., C.,and the rest of the male alphabet, precisely 
alike in stimulating in a similar manner, and to a similar 
degree, the sexual impulse of the female? If we admit any 
differential influence, and if this influence takes effect in the 
sexual union to which courtship is preparatory, we so far admit 
the efficacy of that which Darwin termed sexual selection. 
Let us, however, before proceeding with general con- 
siderations, present one or two examples of the facts which 
observation has furnished with regard to specialized modes 
of behaviour at the time of pairing. Speaking of American 
night-hawks, Audubon says, “ Their manner of flying is a 
good deal modified at the love season. The male employs 
the most wonderful evolutions to give expression to his 
feelings, conducting them with the greatest rapidity and 
agility in sight of his chosen mate, or to put to rout a rival. 
He often rises to a height of a hundred metres and more, and 
his eries become louder and louder as he mounts; then he 
plunges downward with a slanting direction, with wings half 
open, and so rapidly that it seems inevitable that he should be 
dashed to pieces on the ground. But at the right moment, 
sometimes when only a few inches from it, he spreads his wings 
and tail, and, turning, soars upward once more.” * Mr. Strange, 
quoted by Darwin,f says of the satin bower-bird, ‘‘ at times the 
male will chase the female all over the aviary, then go to the 
bower, pick up a gay feather or a large leaf, utter a curious 
kind of note, set all his feathers erect, run round the bower 
and become so excited that his eyes appear ready to start from 
his head; he continues opening first one wing, and then the 
other, uttering a low, whistling note, and, like the domestic 
cock, seems to be picking up something from the ground, until 
at last the female goes quietly towards him.” 
* Quoted by Groos, op. cit., p. 259. 
¢t “ Descent of Man,” vol. ii., p. 77. 
