SEXUAL SELECTION 



553 



In some specimens (A, Fig. 58) large spaces on the upper 

 surface of the wings are colored black, and include irregu- 

 lar white marks; and from this state a complete gradation 

 can be traced into a tolerably perfect ocellus (A'), and this 

 results from the contraction of the irregular blotches of 

 color. In another series of specimens a gradation can be 

 followed from excessively minute white dots, surrounded 

 by a scarcely visible black line (B), into perfectly symmet* 



Fig. 58.— Cyllo leda, Linn., from a drawing by Mr. Trimen, showing- the extreme 

 range of variation in the ocelli. 



A. Specimen, from Mauritius, upper surface of fore-wing. 

 Al. Specimen, from Natal, ditto. 



B. Specimen, from Java, upper surface of hind-wing^. 

 Bl. Specimen, from Mauritms, ditto. 



rical and large ocelli (B').*' In cases like these, the devel- 

 opment of a perfect ocellus does not require a long course 

 of variation and selection. 



"With birds and many other animals, it seems to follow 

 from the comparison of allied species that circular spots are 

 often generated by the breaking up and contraction of stripes. 



^ This woodcut has been engraved from a beautiful drawing, most kindly 

 made for me by Mr. Trimen; see also his description of the wonderful amount 

 of Tsriation in the coloration and shape of the wings of this butterfly, in his 

 "Bhopalocera Africee Anstralis," p. 186 



