133 



SEXUAL SELECTION: BIRDS. 



[Part II. 



It should be particularly observed that each ocellus stands 

 in obvious connection with a dark stripe, or row of dark 

 spots, for both occur indifferently on the same feather. 

 Thus in Fig. 56 stripe A runs to ocellus a y B runs to ocellus 

 b ; stripe C is broken in the upper part and runs down to 

 the next succeeding ocellus, not represented in the wood- 

 cut ; D to the next lower one, and so with the stripes E and 



F. Lastly, the several ocelli 

 are separated from each oth- 

 er by a pale surface bearing 

 irregular black marks. 



I will next describe 

 the other extreme of the 

 series, namely, the first 

 trace of an ocellus. The 

 short secondary wing- 

 feather (Fig. 51), nearest 

 to the body, is marked, 

 like the other feathers, 

 with oblique, longitudi- 

 nal, rather irregular, rows 

 of spots. The lowest spot, 

 or that nearest the shaft, 

 in the five lower rows (ex- 

 cluding the basal row) is 

 a little larger than the 

 other spots in the same 



so that the shading of the ball-and-socket ocelli ought to be slightly 

 different on the different feathers, in order to bring out their full effect, 

 relatively to the incidence of the light. Mr. T. W. Wood, who has the 

 experienced eye of an artist, asserts ('Field,' newspaper, May 28, 18*70, 

 p. 457) that this is the case ; but after carefully examining two mounted 

 specimens (the proper feathers from one having been given to me by Mr. 

 Gould for more accurate comparison) I cannot perceive that this acme 

 of perfection in the shading has been attained ; nor can others to whom 

 I have shown these feathers recognize the fact. 



Fig. 57.— Basal part of the Secondary 

 ' wing-feather, nearest to tbe body. 



