556 



THE DESCENT OF MAN 



ing zones likewise show traces, as may be seen in the draw- 

 ing (Fig. 54), of indentations, or rather breaks. These 

 indentations are common to the Indian and Java peacocks 

 {Pavo cristatus and P. muticus), and they seemed to deserve 

 particular attention, as probably connected with the devel- 

 opment of the ocellus; but for a long time I could not con- 

 jecture their meaning. 



If we admit the principle of gradual evolution, there 



FiG- 54. — Feather of Peacock, about two-thirds of natural size, drawn by 



Mr. Ford. The transparent zone is represented by the outermost 



white zone, confined to the upper end of the disk. 



must formerly have existed many species which presented 

 every successive step between the wonderfully elongated 

 tail-coverts of the peacock and the short tail-coverts of all 

 ordinary birds, and again between the magnificent ocelli of 

 the former, and the simpler ocelli or mere colored spots 

 on other birds; and so with all the other characters of the 



