SEXUAL SELECTION 



665 



above; but I do not feel sure of this. Tliese three marks, 

 b, c, and d, with the intervening bright shades, form to- 

 gether the so-called elliptic ornament. These ornaments, 

 placed parallel to the shaft, manifestly correspond in posi- 

 tion with the ball-and-socket ocelli. Their extremely ele- 

 gant appearance cannot be appreciated in the drawing, as 

 the orange and leaden tints, con- 

 trasting so well with the black 

 marks, cannot be shown. 



Between one of the elliptic orna- 

 ments and a perfect ball-and-socket 

 ocellus, the gradation is so perfect 

 that it is scarcely possible to decide 

 when the latter term ought to be 

 used. The passage from the one 

 into the other is effected by -the 

 elongation and greater curvature 

 in opposite directions of the lower 

 black mark (S, Pig. 59), and more 

 especially of the upper one (c), to- 

 gether with the contraction of the 



'yM'*r^,£Mt££J 



elongated sub-triangular or narrow Fia. eo.— An oceiius in an inter. 



, . _. , 1 J. ii a1 mediate condition between the el- 



mark (of), SO that at last tnese tnree liptlc ornament and the perfect 

 , ^, -^ n . !• • ball-and-sool£et ocellus. 



marks become confluent, forming an 



irregular elliptic ring. This ring is gradually rendered 

 more and more circular and regular, increasing at the 

 same time in diameter. I have here given a drawing 

 (Fig. 60) of the natural size of an ocellus not as yet quite 

 perfect. The lower part of the black ring is much more 

 curved than is the lower mark in the elliptic ornament 

 (ft, Fig. 59). The upper part of the ring consists of two 

 or three separate portions; and there is only a trace of the 

 thickening of the portion which forms the black mark above 

 the white shade. This white shade itself is not as yet much 

 concentrated; and beneath it the surface is brighter colored 

 than in a perfect ball-and-socket ocellus. Even in the most 

 perfect ocelli, traces of the junction of three or four elon- 



