THE PROBLEM OF THE ORIGIN OF SPECIES. 



21 



Explanation of Plate 4 — Continued. 

 B. Female homer, No. K2, mate of No. H4 above. Natural size. Hayashi del., Nov. 1904. 



This female raised from a male bought February 1897. He was fairly thickly chequered, but there was some 

 reduction manifest in the field of lesser coverts. The mother was a stray ( 1898 1, strongly and quite evenly chequered. 



In K2 the scapulars are all double-chequered, but the spots are considerably reduced, paler in front than behind 

 and more fiecky-edged. The spots are fairly long behind, but the points are more or less rounded. There is a pretty 

 well defined row of spots in the third bar, and a few spots of vestigial dimensions and paleness are visible in the fourth 

 row of feathers. On lifting the feathers I find many spots that are wholly concealed. The rest of the small coverts 

 are mostly without visible spots. 



In the male the second bar is cut so straight that no points are seen, while in the female many of these spots are 

 pointed, so as to give a serrate edge, particularly near the middle. 



Measurements of first bar (Dec. 28, 1904). 



The spot of the sixteenth feather is thin, but still quite a spot except for wide, flecky margins. Gradually, as we 

 pass upward, the spots become darker and fuller (i.e., the flecky parts are less in extent), until at the ninth 

 feather we have a well-developed spot which is pointed but ragged-edged distally and proximally. 



Third bar. 



Most of spots have 6 to 8 mm. uncovered. Total length, 10 to 12 mm. In central part of field, where no spots 

 are to be Been, there are many spots entirely concealed which are only seen when feathers overlapping are lifted. 



