BREEDING AND INBREEDIXG FOR COLOR IN SOME DOMESTIC PIGEONS. 97 



obtained. It will be seen by reference to table 71 that lighter but not darker birds 

 resulted. Nine young were certainly intermediate to the two parents in color. 

 Two were as dark as the darker parent, two were similar to the lighter colored 

 parent, and four — "plus the several birds raised by Ollson during the winter of 

 1900-1 — ^had only gray color with two black bars." The number of offspring of 

 hghter color than either parent was therefore probably between 9 and 12. The 

 two sexes are known to have jjeon rcpr(\sented in nearly all of these various groups. 

 It is also notable that the (jrndcr munlier of these lightest colored individuals were 

 from the weakened germs of autumn and winter. 



Adequate color descriptions can be found for only two of the offspring of the 

 sire X daughter mating. One was as light as the lighter parent, the other was 

 intermediate. 



Two of the very darkest of the offspring (of homers 1 and 3) were mated, brother 

 to sister, to see if their dark color might be increased to pure black. It will be seen 

 that progress in this direction — ^loy inbreeding — was not accomplished.'' On the 

 contrary, unexpected white and red appeared, as did also asymmetrical developments 

 in the first 3 offspring of these very young parents. Only 6 offspring were probably as 

 dark as the parents. The young whose color throughout was as dark as that of the 

 parents were from eggs laid February 20, 1902; April 3, 1902; May 12 and 14, 1902; 

 February 2, 1903; April 15, 1903; and June 4, 1903. It is therefore clear that more 

 whites and reds and more defectives arose when the parents were very young and 

 from eggs laid late in the season. 



The inbreeding of the young (of homers 1 and 3) was further carried out as 

 follows: Two of the offspring' of the above pair produced 8 young for which we 

 have some data.' Here it is notable that the first pair of eggs of which we have 

 a record threw birds which were gray with only two bars; and that each of the 

 three succeeding clutches contained a bird with red chequers. (BB 9) 



cTC 1. hatched March 5, 1901; even gray, 2-barred. 

 (fC 2. hatched March 6, 1901; gray, 2-barred. 



"This pair, then (after the two young listed above), produced three successive 

 pairs of young, each time one hlack-chequered and one pale red-chequered." The latter 

 hatched as follows: 



(1) 9 hatched about May 15, 1901; died May 5, 1902. 



(2) — hatched about June 20, 1901; died September 15, 1901. 



(3) — hatched about August 8, 1901. 



One of the above gray 2-barred males {C 1) was mated in 1902 to a related 

 homer. This related female iC) was from the mating recorded in table 76, this 

 latter bird being a sister to both parents oi C 1. It will be seen (table 73) that the 

 further inbreeding of the pair now under consideration gave only 2-barred and 2- 

 reddish-barred offspring, with some infertile eggs. 



The further inbreeding of two of the young from the brother-and-sister mating 

 described in table 72 brings out much more forcefully the effect of inbreeding upon 

 the developmental strength of germs. Onlj^ in their second (and third?) year 



" For further statement on this "selection experiment" see Chapter II (and illustrations), Vol. I. 

 ' cfi; ; and 9 A 1, via K 1 and J 3, from eggs December 28, 1900, and October 26, 1900, respectively. 

 'The complete record of this mating can not be found. The above data are taken from .scattered statements 

 and the one much-abridged summary given above in the author's words. 



