80 ORTHOGENETIC EVOLUTION IN PIGEONS. 



foundations for what is found in Columbula. 32 Moreover, a glance into a wholly 

 different family, the Columbidae, is worth while in a consideration of the status or 

 origin of the oblique wing-bar of C. piqui. 



In a 7-weeks-old common pigeon I find an oblique light streak, in which the 

 feathers are gray, without any edging except a trace of darker gray. 33 All the other 

 feathers (coverts) have a tinge of brown in the gray, and are narrowly edged with 



32 In a Juvenal ground-dove (Chamoepelia) from Santa Martha, United States of Colombia, I find the oblique 

 tract is more strongly marked with spots than other coverts in front of it or behind it. Furthermore, the spots are 

 darker, and the light edge is reduced in width. 



33 In another common pigeon of 15 days — from a cross of a red barb and a red and white jacobin — of blackish-brown 

 color I find feathers with dull reddish tips 1 mm. wide. About 2 or 3 rows of pin-feathers of the oblique tract are 

 beginning to unfold, but are as yet concealed by overlapping lesser coverts, except for 3 or 4 somewhat longer ones 

 near the bend of the wing, which protrude 3 mm. to 5 mm. The interesting point here is that the oblique-tract feathers 

 still show the apical mark, but only about half width, and about half depth of color. 



Explanation of Plate 28. 



A. Left wing of juvenal female Chamoepelia passerina. x 2. Toda del. Completed October 20, 



1903, at age of 12 weeks; but wing was outlined four weeks earlier, at age of 8 weeks, just 

 as a few feathers had been molted. All feathers were finished as first feathers. 



(1) There are 35 spots visible, some of them weak; (2) posterior areas are much like those in C. affinis; (3) all 

 leathers are light-edged. 



B. Feathers corresponding to figures of male shown in plate 27. x 2. Toda del., Sept. 1903. Figs. 



1 to 4 from juvenal female Chamoepelia passerina (left wing, 7 weeks old). 



(1) Pigment is weaker than in adult (see pi. 27); (2) the red- vinous of the adult is here pale vinous-gray 

 or gray; (3) in the feathers corresponding to ti to 13 of plate 27 the dark pigment is found on both sides. These 

 juvenal dark spots are more elongate, as in Columba; mid-rib is light fulvous in color (reminds of young Leptoptila) ; 

 (4) all feathers are edged with pale whitish buff; (5) in 14 to 15 the chequers are pointed behind as in ('. livia 

 (chequered type); evidently homologous in the two forms. 



Fig. 1. Thirteenth feather of plate 27; third row of coverts (middle). Notice two lateral spots or chequers; also 

 median light-buff streak (as in Leptoptila). 



2. Fourteenth of plate 27; middle second row of coverts. Only one chequer. 



3, 4. Fifteenth of plate 27; two upper (inner) long coverts. The median light streak is very narrow. Chequers 

 are pointed and marginal, except for light edge. 



C. Selected feathers from a juvenal Chamoepelia passerina. x 3. Hayashi del., 1905. 



Feathers taken from left wing of mounted skin September 15, 1905, and drawn for transitional phases between 

 central spot and lateral spot or chequer. 



On the wing we find about 5 rows of spots: 



First row, 3 inner tertials. 



Second row, 3 inner long coverts. 



Third row, 5 inner posterior median coverts; one or two feathers are double-spotted; spots on inner side are 

 rudiments. 



Fourth row, 4 and 5 inner mid-median coverts; several of these feathers double-spotted, but the inner spots 

 still small. 



Fifth row, 4 to 6 inner anterior median coverts; all double-spotted, but the inner spots smaller than outer ones. 



In front of these four rows of coverts come the lesser coverts on front edge of wing. These do not show spots on 

 surface when the feathers are in situ, but several of the posterior row of lesser coverts bear spots. 



When the lesser coverts are lifted we find that many of them have the turtle-dove central spot, pointed distally, 

 and some of these present beautiful transitions between the turtle spot and the lateral spots, especially in the posterior 

 row (or two rows) of these coverts. 



The coverts have a whitish edge or tip; those bearing spots and some that have no spots have a mesial rufous 

 streak. This streak is the same as those seen in Zenaida, Geotrygon, European turtle-dove (some young), and in some 

 other species. The streak is sometimes only of the width of the shaft, sometimes it widens a little, extending to differ- 

 ent lengths on the barbs. 



The feathers of the breast are of the turtle type. 

 Fig. C 1. — Feather in next to last row of lesser coverts (near outer edge of wing). 



C 2. — Feather from last row of lesser coverts (at about middle of row). 



C 3, 4. — Feathers from last row of lesser coverts (near outer scapulars). 



C 5. — Feather from anterior row of median coverts (first — outermost — at end of row). 



C 6. — Feather from mid-median row of coverts (second from outer end of row). 



C 7. — Feather from posterior median row or coverts (first — outermost — at end of row). 



