new facts. For the most important of these we are indebted to 
the singularly exact and laborious observations analysed, 
clarified, and interpreted with remarkable insight and sagacity 
of Mr. H. Eliot Howard, one of the keenest Ornithologists of our 
time. He has set forth his case, and interpreted his facts 
with masterly skill, and there seems no escape from his con- 
clusions. Briefly, he has shown that birds of quite sober coloration 
like the warblers, which formed the basis of his investigations, 
engage in displays quite as remarkable, and of precisely the same 
character as in birds of gaily coloured plumage. From this it is 
clear that this wing-play is not prompted by a more or less 
conscious desire to display conspicuously coloured patches of 
colour, for of colour there is none save that of the general hue 
of varying shades of brown, as in the case of the grasshopper 
warbler, for example. Nor is the display, apart from colour, 
to be regarded as a performance slowly perfected through long 
generations through the selection of females, coy and hard to 
” and wing-dis- 
please. We must regard these “ Nuptial flights 
plays, as the outward and visible signs of a state of ecstatic 
amorousness on the part of the males which, by their persistence 
and frequent recurrence, at last arouse sympathetic response in 
the females. They play the part of an aphrodisiac. Without 
them there would be no mating. In my “ Courtship of Animals ” 
those who will may pursue this subject further. 
64 
