22 



ORTHOGENETIC EVOLUTION IN PIGEONS. 



Explanation of Platk 5. 



A. Female homer, No. 3, hatched Mar. 31, 1901. x 0.8. Hayashi del., Nov. 1904. Parents of 

 the three birds of this plate are shown in plate 4. 



Wing from a large bird of fine form; very pale; primaries inclining to whitish. 



The bars in this bird are obscurely subdivided by lines (alternating light and dark narrow bands) or bands that 

 are not perfectly transverse, but inclined so that those of two sides meet at a very obtuse angle (i.e., they are what 

 were later called "fundamental bars." — Ed.). 



Third bar. — First, second, and third feathers each have two spots — both weak and pale, and plainly obsolescent 

 (ragged edges and light lines crossing them). Lower down only one spot to the feather (lower web), pale and increas- 

 ingly thin and roughly outlined. Elsewhere in front of this bar the color is pure — very pale gray; no spots to be seen. 

 A few vestiges found on lifting feathers. 



Scapulars: In front no spots; in middle spots are pale reduced vestiges; behind they become more distinct, but 

 they are everywhere weak and without clear outlines. 



Second bar. — On right side some of middle spots are pointed, but on left side corresponding feathers show spots 

 with points disappearing. 



Feather 2. Length of spot, 13, exposed; total length, 20 mm. 

 3 and 4. Length of spot, 13, exposed. 

 5. Length of spot, 11, exposed; point obsolescent. 



Length of spot, 21, exposed; point intact but distal edge flecky. 

 Length of spot, 12, exposed; point cut off as an island. 

 About same, but island thinner. 

 About same, but thinner. 

 Shorter and still thinner. 

 Length 8 mm., pale and flecky throughout. 

 12 to 15. Thinner and vanishing on last. 

 About 4 mm. of the mid-spots are covered. 



Measurements of first bar. 



6. 



7. 



8. 



9. 

 10. 

 11. 



Eighth spot is decidedly paler than in seventh feather. This sudden drop to pale spots at eighth seen again 

 in figure U of plate 4. 



This bird has made a decided advance over the dam, but she is not quite so far along as the sire. The second 

 and third bars are narrower than in the dam. The first bar is wider than in the sire, but the second is about the same. 



