78 ORTHOGENETIC EVOLUTION IN PIGEONS. 



to be visible, except when the feathers are parted. The spots run into narrow and 

 slender pointed streaks towards the abdomen, and then disappear wholly on the 

 abdomen. The under tail-coverts show the same spots in brownish gray. The 

 distribution of red on the primaries, and elsewhere on the wing, is best shown in 

 plate 30. 



The Juvenal Chanwepelia passerina presents some interesting conditions. The 

 coloration is weaker than that of the adult, but much more nearly approximates 

 that of the female than that of the male. The spots or chequers resemble more 

 than do those of the adult the posteriorly pointed chequers of the chequered rock- 

 pigeons (Columba affinis). The feathers are all pale-edged (pi. 28, fig. B). The 

 female plumage-pattern is in many respects an intermediate of the Juvenal and 

 the male (pi. 27, fig. B). 



In these Juvenal plumages one also finds convincing transitional stages, linking 

 the central turtle-dove spot with the modified spots or chequers (pi. 28). 



Still other species of Chamcepelia exhibit similar or more modified patterns. In 

 Ch. buckleyi, according to Salvador!, brown and black largely replace vinous and 

 cinnamon, respectively, of the Ch. passerina coloration. The breast-feathers have 



EXPLANATION OF PLATE 27. 



A. Fifteen selected feathers from left wing, neck, and breast of an adult male Chamapelia passerina. 



All figures x 2. Toda del., Mar. 1903. 



Fia. 1. From mid-front neck. Shows turtle dark center in typical form a dark-gray triangular area, with a broad 

 vinous edge. 



2. Mid lower front neck. The turtle center equally perfect in definition; color and shape same as above. 



3. Mid-breast, between front angles of wings. Spot acuminate, pale gray. 



4. From abdomen. Spot much reduced, pale gray. 



5. Middle of side of neck, in ring region; central spot has vanished. 



6. Small covert near front edge of left wing, next to scapulars. The turtle center is plain, though not quite 



so dark as in figure 1. Dusky gray and pointed. 



7. From close behind figure 6. An obscure small dull-gray spot on left (lower) web, on which side the central 



spot retreats a little. 



8. Nearer bend of wing. The dark chequer is here larger and stronger; the central spot retreats more on this, 



the side bearing the chequer. 



9. From close beside figure 8. 



10. From just behind bend of wing. 



Both 9 and 10 show the growth of the chequer and a one-sided reduction of the central spot. In all the 

 chequers basal edge is less sharply marked than apical edge; the chequer seems to blend witli the dark 

 center. 



11. From just behind bend of wing, shows plain fusion of chequer and center. 



12. Middle of small coverts, fusion more complete. 



13. From middle of third row of coverts, only a rudiment of a chequer, and an obscurely outlined center. 



14. From middle of second row of coverts; dark center still perceptible. 



15. The two uppermost long coverts; chequers more elongated. 



Some feathers corresponding (13 to 15) to these, from Juvenal female and adult female, are shown in plate 28. 



B. Five feathers corresponding to figures from male shown above. Toda del., Sept. 1903. x 2. 



Figs, la to 5o from adult female Ch. passerina, same date. 



Figs, la and 5a correspond to figs. 11 and 12 of the adult male (pi. 27). 



Figs. 3a to 5a correspond to 2 to 4 of the Juvenal female described and figured above, and to plate 27, figs. 14 to 

 16 (fig. 15 there represents two feathers). 



The young have the distal third of the feather more brown. Adults have the distal third of feather more gray. 

 The spots in the adults are less like typical chequers. 



(1) The female is much nearer the young in general color than is the male. 



(2) The spots point more directly backward i.e., less transversely, and more like C. affinis. 



(3) The edges of the feathers are more distinctly dark. 



(4) In figure 5a a small spot is seen on right edge of feather another more primitive feature not found in the male . 



