90 ORTHOGENETIC EVOLUTION IN PIGEONS. 



The marking of the normal male shows that this species stands below Geopelia 

 humeralis in having: (1) a smaller size; (2) a lesser area on the breast and neck that 

 is free from bars; (3) the unbarred part pale vinous instead of gray; (4) the vinous 

 area extends downward to about the same level as does the gray in G. humeralis; 

 it then fades into the whitish of the abdomen {G. humeralis has lower breast only 

 pale vinous); the vinous breast probably stands below the gray breast; (5) there 

 are more barred feathers, and more bars to the feather. 



On the wings and back the bars are apical edge-bars, as in G. humeralis, and are 

 about the same in color and appearance in the two forms. In young G. humeralis, 

 as in this species, the black bar is not terminal, but stands within the apical pale- 

 whitish bar. The black apical bar is therefore secondary, the pale-edge bar primary. 

 In the adult of this species I find on the neck many feathers which retain the white 

 apical edge, while some others show the apical black bar in all stages of obsolescence. 

 The pale or white edge of the neck-feathers is therefore a still later modification, the 

 feathers having lost the juvenal pale edge and are now in process of losing the black 

 edge, which is homologous with the black edge of the wing-feathers. The neck- 

 feathers are, then, higher in development than the wing and back feathers. 



As we pass up from the back to the neck we see the black edge is at first present 

 in full width; on the lower hind-neck we find it looking a little thinner and lower; 



Explanation of Plate 37. 

 A. Adult male Geopelia striata, x 1.4. Hayashi del., Nov. 1902. 



Shows the extent of the unbarred breast region in the normal type of this species. Compare with the more 

 complete barring of juvenal and adult atavistic female (pi. 42). (See text.) 



The feathers are all shown with white edges, as they appeared to Mr. Hayashi, but the black apical edge is for 

 the most part present, though inconspicuous. 



1 to 7. Separate feathers from normal G. striata. 



A. Upper part of mid-back of neck. Bars are only 3, the basal one very shadowy. The mid-back neck-feathers are 



all less differentiated; they have fewer bars and the color of these is intermediate between that of body 

 and wing feathers and of the feathers of the side of the neck, where differentiation is sharpest. The 

 black bars are here only dark brown and the white bars are pale buff. 



B. Shows the height of differentiation in mid-back of neck. 



C. An ordinary feather from middle of back of body. It has black apical edge-bar, and just inside this an obscure 



buff bar. 



D. Middle height of neck, right side, front edge of barred feathers. Front half of feather is not barred, except that 



the first black bar runs over the mid-rib a little. This half is vinous. There are four half-bars. The 

 apical black bar is only barely recognizable to the naked eye (on the barred side), and extends just a 

 little over the mid-rib and soon vanishes. The artist at fust failed to sec and draw the black apical bar. 



E and F. Middle right side of neck, where bars are best developed in number and color, the pale bars being almost 

 white and the dark bars black. Figure E has a thin black edge, but figure F has only a trace of it on 

 the left side. 



G. Just below middle left side of neck, similar to figure F. To the naked eye there is no apical black, but with a 

 lens I can detect just a touch of blackish on the tips of some of the barbs. 

 Note that this species has the whole side of the body and under wing-coverts multibarred. 



Explanation of Plate 38. 



A. Juvenal Geopelia striata, x 1.5. Hayashi del., Oct. 1902. 



This first plumage shows the bars completely circling the front of the neck, but they are not so well marked in 

 the middle region, which is dl stined to be even unbarred and of vinous color in the second plumage. This condition 

 of bars is permanent in one species, <!. tranquilla. 



B. Adult female Geopelia striata, x 1.5. Hayashi del., Nov. 1902. 



This represents a variation from the normal shown in plate 37, and approaches the juvenal condition in the bars 

 crossing the front of the neck; but these bars are faint in the middle line. 



