Chap. XIV. Birds—Gradation of Characters. 435 



shaft to one of the ocelli. The spots are generally elongated in a 



line transverse to the row in which they stand. They often 



become confluent, either in the line of the row— and then they 



form a longitudinal stripe— or transversely, that is, with the 



spots in the adjoining 



rows, and then they 



form transverse stripes. 



A spot sometimes 



breaks up into smaller 



spots, which still stand 



in their proper places. 



It will be convenient 

 first to describe a per- 

 fect ball - and - socket 

 ocellus. This consists 

 of an intensely black, 

 circular ring, surround- 

 ing a space shaded so 

 as exactly to resemble 

 a ball. The figure here 

 given has been ad- 

 mirably drawn by Mr. 

 Ford and well engraved, 

 but a woodcut cannot 

 exhibit the exquisite 

 shading of the original. 

 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 

 enclosed ball ; it is also 

 sometimes broken to- 

 wards the base on the 

 right hand. These 



little breaks have an important meaning. The ring is always 

 much thickened, with the edges ill-defined towards the left- 

 hand upper corner, the feather being held erect, in the posi- 

 tion in which it is here drawn. Beneath this thickened part 

 there is on the surface of the ball an oblique almost pure- white 

 mark, which shades off downwards into a pale-leaden hue, and 

 this into yellowish and brown tints, which insensibly become 



Fie:. 57. Part of secondary wing-feather of Argus-, 

 pheasant, shewing two perfect ocelli, a and b 

 A, B, C, D, &c, are dark stripes running obliquely 

 down, each to an ocellus. 



[Much of the web on both sid^s, esp daily to the 

 left of the shaft, has been cut off.] 



