THE TURTLE-DOVE PATTERN IN OTHER ORDERS OF BIRDS. 131 



The middle interscapular feathers show the slightly modified turtle-dove pattern. 

 The dark center and the pale tip are both present, the latter having extended upon 

 the lateral margins of the feather. Coincident with the earlier extensions of these 

 lateral margins, a slender shaft-streak makes its appearance. Other feathers show 

 that further increase of the lateral margin is accompanied by enlargement of the 

 median shaft-streak. 



In the feathers of this bird it is clear that the V-shaped figure arises from the 

 turtle-dove pattern. It is not a "tilted" bar, as Keeler believed (pi. 61, figs. 1 

 to 11). 



The wings of the juvenal pheasant show dark centers, light edges, and a very 

 simple type of barring. This barring is present in all grades, from a few flecks to 

 fully formed bars. This light-colored bar is more complete on the long coverts than 

 on the primary coverts (pi. 61, fig. 12). The wings of still younger birds (pi. 79, 

 fig. A) show that the color of the pale edge is practically identical with that of the 

 down. 



Phasianus wallachii. — In this species the pattern is, in the main, similar to that 

 just described for P. torquatus, but the turtle type is here still further modified. 

 Here, too, the males stand above the females in the extent to which the ancestral 

 pattern has been transformed (pi. 66). 



ON THE EVOLUTION OF THE OCELLUS OF THE ARGUS PHEASANT AND THE PEACOCK. 33 



Several instances of the origin of white spots from preexisting white transverse 

 bars have already been noted (the immediately preceding pages, and Geopelia 

 cuneata, Chapter X). Because of its relation to the present subject it is interesting 

 to find indications that this rule of origin holds for one of the Phasianidse — Numida 

 coronata (pi. 64). It is of even greater interest to be able, in the Simla horned 

 pheasant — a form showing large, distinct, white ocelli — to show that the smaller 

 white spots of some of its feathers are actually parts of white transverse bars (pi. 

 67, fig. 1). 



Other feathers of this same species (Tragopan melanocephalus) offer evidence 

 that the large, single, subterminal white spot, which is borne near the tip, represents 

 a fusion of several bars. And in these same feathers it is quite clear that the dark 

 center is primary, and bars and spots secondary in origin (pi. 67, figs. 2 to 4). 



As is well known, the argus-pheasants (Polyplectron) and the peacock (Pavo 

 cristalus) show in many of their feathers eye-spots, or ocelli, of fine finish and of 

 brilliant color. The bronze-winged pigeon (Phaps chalcoptera) seems to present 

 the beginnings of such marks when a brilliant iridescence is superposed upon the 

 black of its considerably reduced chequers (pi. 6, fig. A). 



In Polyplectron bicalcaratum the female retains unmistakable elements of the 

 dark-centered feather; the male has made a greater departure from earlier condi- 

 tions, having more ocelli, and also ocelli of higher finish (pi. 68). A highly finished 

 black border surrounds each ocellus in this species. In the bronze-wing a similar 

 black border is present on the "terminal end" of the spot, half converting it into 

 an ocellate form. 



33 The author grouped together certain materials on this topic, and indicated "a paper to be worked out on this 

 subject." This paper was not completed. A few original observations, together with the illustrations, and the more 

 extensive review of Kerschner's work on the subject, will at least make clear the author's opinion, namely, that this 

 finely finished and most remarkable color-mark takes its departure from a feather with a dark center; that it does 

 not arise from the coalescence of two lateral spots. — Ed. 



