HISTORY OF THE CANARY 



35 



hcterozygotc D R is crossed with the recessive 

 R R e:)ch flomiiianl and each recessive gamete 

 arising from the former can unite only with a 

 recessive gamete formed by the latter. Con- 

 sequently, we should look for the production of 

 equal numbers of zygotes of the constitution 

 D R and R R." 



This is what happens {see Group III., 

 2, 3, 4, 5). Hair the oifspring are pure 

 pink-eyecl recessives, and tlie other half 

 are dark-ej^ed dominants which may all 

 be proved to carry the pink-eyed charac- 

 ter, i.e., are heterozygotes. 



DR ) 



X I = DR -F R R 

 RR j 



" Similarly, when the heterozygote D R is 

 crossed Willi tlie pure dominant form D D 

 we should from theory expect all tlie off- 

 spring to be dominant in form and one- 



half of them to be pure dominant. Here 

 again experiment has borne out theory. 

 The generalisation known as the principle of 

 gametic segregation may be regarded as firmly 

 established on the phenomena exhibited by 

 plants and animals when strains are crossed 

 wliich possess pairs of dilTcrentiating characters. 

 Whether the principle applies universally 

 or not can only be answered by subsequent 

 experiments." 



In this position we leave the important 

 subject of inheritance in Canaries, with the 

 hope that fanciers may be induced to study 

 the theoretical side of their hobby, and 

 invariably to make full notes of all their 

 matings, for such points as we have dis- 

 cussed, besides being of value for breeding 

 purposes, are full of significance with 

 respect to inheritance generally, and details 

 which seem valueless to-day may be the 

 basis of the great discoveries of to-morrow. 



DR. GALLOWAY'S CLEAR YELLOW SISKIN-CANARY. 



Winner of many first prizes 190S-10 and also Championship Diploma for Best 

 Hybrid, Crystal Palace, 1909 and 1910. 



