COLOURS PRODUCED BY COURTSHIP 293 



is therefore probable that the females take the more 

 active share in the wooing, and that the males have 

 exercised their aesthetic preferences, and have thus 

 caused their mates to be more beautiful than them- 

 selves. These striking facts were brought before Mr. 

 Darwin by Professor Meldola, who informs me that 

 he has confirmed the facts by his own observation in 

 the field. 



During the past summer (1889) I have seized every 

 available opportunity of watching the wooing of our 

 common- white butterflies (Pieris. brassicce, P. rap<e, 

 and P. napi), and I can quite confirm Professor 

 Meldola's prediction. The females were far more 

 ardent than the males, and when the courtship came 

 to an abrupt termination, as it generally did, it was 

 invariably due to the coyness of the males. These 

 facts strongly support the opinion that the beauty of 

 the females has been gradually produced by the pre- 

 ferences of the males. 1 



1 S. B. J. Skertchly has recently (Ann. and Mag. Nat. Hist. Sept. 

 1889, pp. 209 et seq.) described a case in which the rare female of 

 Ornithoptera brookeana eagerly and persistently courted a male, 

 although males are more abundant and far more brilliantly coloured. 

 Professor Moseley, on the other hand, describes the courtship of 

 Ornithoptera poseidon in the following words : ' I once . . . was 

 lucky enough to find a flock of about a dozen males, fluttering round 

 and mobbing a single female. They were then hovering slowly, 

 quite close to the ground, and were easily caught. The female had 

 thus a large body of gaudy admirers from which to make her choice.' 

 (A Naturalist on the ' Clmllenger,' 1 p. 373.) The wide difference be- 

 tween these two accounts of courtship in closely allied species, proves 

 the importance of making many observations before we can hope to 

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