THE TURTLE-DOVE PATTERN IN THE PHYLOGENY OF PIGEONS. 71 



this light edge is homologous with the whole fulvous margin. This margin has 

 been widening and has now become much wider than it was originally. 17 



In the young of turtxir, the dark center is reduced — i.e., it retreats farther from 

 the feather margin (fig. 3, pi. 22) — and here the rufous lateral edges are wider than 

 in orientalis, the rufous seeming to take the place of the retreating black. 



In these feathers the tip is cinnamon-brown, only a shade darker than the down 

 itself, and is 1.3 mm. wide at the center, from which it narrows outward. There is 

 no concentration of dark pigment bordering the proximal side of this tip — such as 

 I see in Streptopelia humilis, Stigmatopelia senegalensis, Streptopelia damarensis (figs. 

 4 and 5, pi. 22), and other forms that have lost or much reduced the dark center. 



The third long covert (counted downward) may be said to have the pattern in 

 typical form for this European species. Here the feather's base is gray, becoming 

 distally dark gray, and passes into black in the distal half of the center, the black 

 becoming pointed and reduced to a shaft-line which reaches, but does not extend 

 into, the light tip. The rufous margins are of very considerable width, easily attain- 

 ing 5 mm. The rufous of the margin has a sprinkling of blackish beginning on its 

 inner half and increasing towards the dark center, thus blending with the center, 

 so that we have no sharp boundary. 



In the breast-feathers of a juvenal turtur (about 2 weeks old), and in the same 

 feather of its nest-mate, I find what I had not previously noticed in other young 

 turtles — a pale, whitish shaft, or a narrow shaft-streak, expanding at the feather's 

 tip into a triangular cinnamon-brown spot, comparable in shape and position with 

 the apical spot seen in the robin and some other forms. (Later, I recognize in this 

 mark of the turtle-dove an indication of the guinea-pigeon's apical mark of white.) 



The breast-feathers are all tipped with the cinnamon-brown and the median 

 spot forms part of the tip or pale edge; i.e., the color of the spot and the edge are 

 the same and continuous. In other specimens of European turtles I do not recognize 

 this median streak and spot. Neither do I see it in the Japanese turtles. 



Among the speckled-neck doves (Spilopelia) we find the black center further 

 reduced. In the Surate turtle of Latham (Sp. suratensis) Salvadori (p. 445) notes 

 that the "black contracts to a central streak," and that this reduction is accompa- 

 nied by a modification (in the scapulars and upper back feathers) of the pale edge 

 into "two pale vinous isabelline spots" 18 (pi. 24, Vol. II); in the tiger turtle-dove 



"The author later noted the neck-roark, dark center and pale tip of orienlalis and turtur in Turtur ferrago. 

 Salvadori's description (pp. 400 and 408) makes it clear that all these are also present in the two remaining species, 

 T. isabellinus and T. lugens of the genus Turtur. — Ed. 



18 The Surate turtle of Latham (Spilopelia suratensis), in its juvenal stage, represents, in its color-pattern, quite 

 closely >S>. tigrina. The female does this more closely than the male. I have a pair now (July 1910) in full juvenal 

 plumage. The male shows in its scapulars a decided step towards the adult pattern— most of these feathers showing 

 the "two pale vinous isabelline terminal spots, enlarging and spreading upon each side of the feather" (vide Salvadori, 

 p. 445). The coverts of the whole wing exhibit the "dark mesial stripes" of the tiger turtle. The female shows less 

 of the pale isabelline spots on the back, and its wing-pattern closely resembles that of the tiger turtle. 



I have preserved three of the posterior scapulars of the right side of the young male in order to show the spots 

 and at the same time to show that these spots are nothing but transverse bars in origin. Every feather in the juvenal 

 stage of all pigeons has a more or less pale-brownish apical edge. This apical bar is followed in the Surate turtle by 

 a dark bar, and this by another pale bar. It is this subterminal second pale bar out of whirl, the pale-isabelline spots 

 arise. The evidence (if this is plainly seen in these plucked juvenal feathers; the idenl ity of the spot with the second 

 pale bar is well shown. The enlargement of the lateral elements of the bar takes place through the suppression of 

 one to several of the subterminal dark bars, the light bars thus coalescing to form the two "terminal spots." 



The case of the .Surate turtle is not an isolated case. Out of these same transverse bars arise the pair of white 

 dots on each of the wing-coverts in the little diamond-dove (Gcopeha cuneata), as I have found out by studying the 

 juvenal plumage. These transverse bars play a great role in giving rise by modification, fusion, etc., to specific 

 color-types. 

 6 



