BREEDING AND INBREEDING FOR COLOR IN SOME DOMESTIC PIGEONS. 99 



The color records are adequate, or nearly so, in the cases of 22 young. They fall 

 into the following groups: Intermediate, 12(+?4); hghter than lighter parent, 

 5(+?2); darker than darker i^arent, 1; infertile 4. The seasonal distribution of 

 these very light colored birds is of chief interest, and an examination of the ap- 

 pended table (76) shows that 4 of the total of 5 arose from the first or the last clutch 

 (hatched) of the year; the other very light colored bird hatched from the last clutch 

 of which we have a record in 1904. The four eggs that failed to develop were all 

 from the extreme end of the year. Three of these lightest colored offspring are 

 from the two clutches immediately adjoining a pair of infertile eggs. 



Still another of the offspring (marked F 1) of the mating d'B 1 x 9A 1 was 

 mated with a consort that seems^" to be / ^ (from egg of January 24, 1900) of 

 homers 1 and 3 (see table 71). The parents oi 1 2 are therefore at the same 

 time all of the grandparents oi F 1. F 1 was gray with 2 bars; the female 12 was 

 chequered a little less than her least chequered parent (Hom. 3). Only 4 eggs are 

 recorded, but it is of interest to note that the first pair (Feb. 3 and 5, 1900) of these 

 (also ?first in life) were incapable of hatching, and that the second pair of eggs 

 (Mar. 5 and 7, 1900) both hatched birds with the reduced barring — 2 bars, without 

 chequers. (BB 9) 



Records were kept for a few other pairs of inbreeding homers, but those pairs 

 were not confined to a cote; and since such females might secure fertilization from 

 other males (as noted by the author), all such pairings have been excluded from 

 consideration in these pages. 



BLACK. RED, AND GRAY BARBS FROM BLACK PARENTS. 



The following experience with black barbs (a domestic variety) indicates that 

 the sliding scale of fertihty elsewhere elaborated is accompanied bj^ a change or 

 reversal of the dominance of color. The dominant black becomes but partially 

 dominant under a series of conditions that weakens germs, i.e., inbreeding, late 

 season, and immaturity of parents (possibly also, second egg of the clutch). Red 

 and gray colors appear under these conditions, as will be seen by an examination of 

 the data of tables 77 and 78. 



A red male (/l) from these black barbs was mated in 1906 with a red-and-white 

 barb. It is certainly interesting, in view of the foregoing situation, that this 

 immature red male mated to a (possibly immature) red-and-white bird should 

 throw nearly or quite as many black as red, whereas the several inbred black barbs 

 mated to other black barbs threw nearly as many non-black (red and gray) as black; 

 and indeed a much higher proportion of non-black in the periods of "weakest 

 germs." These data are included in table 78. 



In all of the above matings w^here more than one color appeared, it will be 

 observed that there hatched 15 black, 11 red, and 4 gray. But in spite of this 

 predominance of black (even where black was not the exclusive or only color) , the 

 last egg of the season was never known to produce a black, though 3 such threw 

 red and 1 graj^ (2 did not develop). And, further, where two colors appear from a 

 single clutch the second egg never produced the predominant black, though the 

 rarer red bears such a relation in three cases. It is not surprising to find black 



'° In this case the editor is not positive that he has tlie right history of the birds concerned in the mating. It is 

 probably right as stated. 



