THE TURTLE-DOVE PATTERN IN THE PHYLOGENY OF PIGEONS. 113 



larger guinea-marks — i.e., the white of the guinea-mark has made a deeper invasion 

 into the black feathers that still persist. 



That stage of the guinea-mark in which the complete separation of the dark 

 center into two marginal chequers is effected can be seen in the scapulars and coverts 

 of the juvenal common pigeon. The series of feathers shown in plate 55, figures 

 1 to 11, shows different stages of the further invasion of the black after the dark 

 center is divided. In the outer (lower) larger coverts the inner chequer is quite 

 gone (figs. 7 and 8), and where the depigmentation is much advanced, as in some 

 of the scapulars and lesser coverts, the vestiges of the chequers become marginal 

 streaks (figs. 4 and 11). 



One of the long coverts of an adult male satinette-dove has been drawn (pi. 55, 

 fig. 12). It shows the two chequers bleached in their central portions, leaving the 

 marginal portions still pigmented. This bleaching is carried to different extents 

 in different feathers in this species, and the results are interesting for comparison 

 with the marginal and subapical marks in geopelias, the tambourine-dove, and 

 other forms. 



The turtle-dove neck-mark is by no means lost in common pigeons. By lifting 

 the feathers one sees that their bases are blacker on the sides of the neck than else- 

 where. This is a hint to the turtle-dove neck-mark. In a hybrid common pigeon X 

 Turtur orientalis this same mark shows more strongly. 35 



Color and Pattern in Domestic Pigeons According to Prutz. 38 



Mr. Priitz has studied the colors and the color-patterns of many of the domestic 

 varieties of the pigeon with considerable care and has undertaken to give the general 

 laws of coloration for the whole group of domestic pigeons. He has sought to define 

 genetic relationships, to state the correlations and sequences in colors, and to give 

 the behavior of colors in cases of crossing. Some of the conclusions appeal to my 

 interest, and seem to bear upon my own results. 



Priitz asserts that "all white in pigeons is the same. ... It is pure white 

 without any admixture of any other color." It is absence of pigment, and must 

 be regarded as albinism 37 (pages 294, 295). On this point I may record a doubt 

 whether any such "pure white" is found in normal pigeons. There is certainly a 

 plain trace of pigment in many so-called "white doves." 



Brown, red, and yellow. — These, according to this author (page 295), may 

 properly be regarded as one color. Between brown and red on the one side and 

 yellow on the other there is, to be sure, quite a gap; but birds that bridge this gap 

 are not entirely wanting, although they are rarely met with. "As a peculiarity of 

 the yellow color, it deserves mention that the yellow dove is hatched with very 

 scanty down, almost naked, and is weak in constitution and generally of the female 

 sex." 38 The same is said to hold for the leather or chocolate color, which arises 

 from crossing black and yellow, or black and red. 



"For further illustration of neck-mark in common pigeons, see Chap. XVII, and plate 32 and text-fig. 2, Vol. II. 



36 Gustav Priitz, Die Mustertauben Buch. (The quoted matter is from Priitz; the statements not in quotation 

 marks are comments, or original observations, of the author. — Ed.) 



•"It is stated that "white" is always "albinism," but it does not necessarily mean a "weak constitution." 



38 Darwin (Animals and Plants, Vol.1, page 210) earlier noted that "young pigeons of all breeds, which when mature 

 become white, yellow, silver (extremely pale blue), or dun-coloured, are born almost naked: whereas other coloured 

 pigeons are born well-clothed with down." Darwin considered this "an inexplicable case of correlation." 



