BIRDS--_continued_.
Choice exerted by the female--Length of courtship--Unpaired
birds--Mental qualities and taste for the beautiful--Preference
or antipathy shewn by the female for particular males--
Variability of birds--Variations sometimes abrupt--Laws
of variation--Formation of ocelli--Gradations of
character--Case of Peacock, Argus pheasant, and Urosticte 99-153