THE TURTLE-DOVE PATTERN IN OTHER ORDERS OF BIRDS. 



119 



On the question of the primitive color or colors in birds Mr. Keeler's 7 tabulation 

 (page 144) of the frequencies of occurrence of the various colors, in the 209 genera 

 of North American land birds, is of interest. The distribution of the colors is as 

 shown herewith: 



Brown or gray occurs in almost every genus, either in the young or in the adult 

 stage; these colors are generally present in species in which the markings are not 

 highly developed, and they frequently occur in the young of species highly special- 

 ized in the adult. All this, it is noted, indicates that brown and gray are primitive 

 colors. 



'The tendency would be to progress from such mixed shades as brown and gray 

 to the pure colors." Taking brown as a primitive color, and the discovery of 

 Kriikenberg that brown is chiefly due to two apparently distinct pigments (zoorubin 

 and pseudozoorubin), Keeler formulates a "theory of bird colors." 



The "streaked feather" is held to be "the most primitive form," and the more 

 central location of color he considers to be due to secondary pigmentation. Keeler 

 accepts Eimer's view that markings first appeared in the hind-body, and then 

 gradually passed forward. All of this is contradicted by the elucidation of the 

 sequence of pattern in the pigeons. 



In a general theory of animal coloration Tylor 8 claimed, and Wallace accepted 

 the view, that the development of marks and patterns depends on "organization," 

 following the chief lines of "structure" and changing at points and regions where 

 function changes. 



Tylor held that "spots" constituted the primitive form of ornamentation; that 

 "lines" or "bands" are formed by the confluence of spots; and that by confluence 

 of "bands" arise "patches," or "uniform-color" over larger or smaller surfaces of 

 the body. 9 



Tylor says : 



If we take highly decorated species that is, animals marked by alternate dark or 

 light bands or spots, such as the zebra, some deer, or the carnivora we find, first, that the 

 region of the spinal column is marked by a dark stripe; secondly, that the regions of the 

 appendages, or limbs, are differently marked ; thirdly, that the flanks are striped or spotted 

 along or between the regions of the lines of the ribs; fourthly, that the shoulder and hip 



1 Chas. A. Keeler, Evolution of the Colors of North American Land Birds, 1893. 



8 Coloration in Animals and Plants, London, 1886. 



* Examples given are: Young lion and tiger both spotted. Java hog (Sus rittaius), very young, have bands, but 

 spots on shoulders and thighs. "The spots run into stripes us animal grows older; then stripes expand, coalfcf. and 

 the animal becomes of a uniform dark brown." This agrees with Eimer's law, if the "stripes" are bands or cross- 

 stripes. Pigs and tapirs are banded or spotted when young. A young Tapiritx buirrli was covered with white spots 

 in "longitudinal rows," here and there forming short stripes. So many of the species of deer are spotted when young 

 that Darwin concluded that the ancestral form must have been spotted. According to Darwin, the horse descended 

 from a striped animal, and is often spotted (dappled). Darwin also pointed out that ocelli may arise from spots or bars. 

 9 



