IWKKOIM; AND i\r.i;i;i:m\<: mi; coi.ou IN smn; IMI\II:-,TI<- PIGEONS. '.'7 



obtained. It will he seen by reference to table 71 that lit/htfr but not ilur/.t r bird.- 

 resulted. Nine young \vere 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 \\inter oi 

 1 !)()()-! had only gray color with two black bat-." The number of offspring of 

 lighter color than either parent, was therefore probably between '.) and 12. The 

 two sexes are known to have been represented in nearly all of these variou< groups. 

 It is also notable that the f/mi/rr niiniltcr of llu'.w lii/hh'xt colored iiidiridmilx were 

 from the weakened yt'rnix of autumn timl winter. 



Ade((iiate 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, brot her 

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

 that progress in t his direction by inbreeding was not accomplished/' On the 

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

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

 dark as the parent's. The young whose color throughout was as dark as that of t he 

 parents were from eggs laid February 20, 1902; April 3, 11)02; May 12 and 14, 1902; 

 February 2, 1903; April 15, 1903; and June 1, l!)03. 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 ot the young (of homers 1 and 3) was further carried out a- 

 follows: Two of the offspring 7 of the above pair produced S young for \\hich we 

 have some data. 8 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) 



(fC 1. hatched March .">, 111(11; even i;rny, l!-l)arred. 

 C?(' -'. hatched March li, 11101; ray, iMwnvd. 



'This pair, then (after the two young listed above), produced three sticce--ive 

 pairs of young, each time one black-chequered and our />nlc red-ehei/nen-d." The latter 

 hatched as follows: 



(1) 9 hatched alxmt May 1.1. 11101 ; died May ". l'.H)2. 



(2) hatched about June 20, 11101 : di< -d September 15, lliol. 



(3) hatched about Aucu-t s, 11)01. 



One of the above gray 2-barred males (C 1) was mated in 1 ( .)02 to a related 

 homer. This related female (T) was from the mating recorded in table 7li. this 

 latter bird being a sister to both parents of (' 1. It will be seen (table 7.'!. that the 

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

 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. Only in their second (and third? 1 year 



6 For further statement on this ''selection experiment " see Chapter II land illustrations'. Vol. I. 



7 tflil and 9^4 /, via A" / and ./ .'. from es December _'S. 1!M)0, and October _>!>. HUM), respectively. 



^ The complete record of this mating can not be found. The above data are taken li :cd statement- 



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



