SEXUAL SELECTION 



561 



The wing-featliers, bearing tlie ocelli, are covered with 

 dark stripes (Fig. 67) or with rows of dark spots (Fig. 59), 

 each stripe or row of spots running obliquely down the 

 outer side of the shaft to one of the ocelli. The spots are 

 generally elongated in a line transverse to the row in which 

 they stand. They often be- ^ 



come confluent, either in 

 the line of the row — and 

 then they form a longitu- 

 dinal stripe — or transverse- 

 ly, that is, with the spots 

 in the adjoining rows, and 

 then they form transverse 

 stripes. A spot sometimes ^ 

 breaks up into smallerspots, ♦' 

 which still stand in their 

 proper places. 



It will be convenient 

 first to describe a perfect 

 ball - and - socket ocellus. 

 This consists of an in- 

 tensely black circular ring, 

 surrounding a space shaded 

 so as exactly to resemble 

 a ball. The figure here 

 given has been admirably 

 drawn by Mr. Ford and 



well engraved, but a wood- . ^°- 57— Part of secondary -wins-feather of 



° ' Argus pheasant, showing two perfect ocelli, a 



cut cannot exhibit the ex- »?" 6. a, B, C, D, etc., are dark stripes run- 



ning obliquely down, each to an ocellus. 



quisite shading of the origi- ^ %"<=,'' °'*?^ ^S*'^?1''°S^ ^'^^\' especially 



^ ° "to the left of the shaft, has been cut oft.] 



nal. The ring is almost 



always slightly broken or interrupted (see Fig. 57) at 

 a point in the upper half, a little to the right of, and 

 above the white shade on the inclosed ball; it is also some- 

 times broken toward the base on the right hand. These 

 little breaks have an important meaning. The ring is al- 

 ways much thickened, with the edges ill- defined toward the 



