No. 645] 



HYBRIDS OF THE CANARY 



327 



the case of cross No. 1 (yellow canary ? X California 

 linnet c^), the notes of the hybrids are intermediate in 

 timbre between those of the parents. 



We now come to the question as to how these hybrids 

 compare with other canary-finch hybrids, and in how 

 far they conform with Mendel's laws of inheritance. It 

 will be noticed that in the case of the canary-California 

 linnet hybrids, as in many mammalian crosses, dark 

 color is completely dominant over light color, but the 

 number of offspring (7) is too small to warrant the con- 

 clusion that this will always prove to be the case. On 

 the other hand, as regards the canary-willow goldfinch 

 hybrids, there is no complete dominance of one color, 

 the hybrids in this case showing a similar variability 

 to that of canary-European goldfinch hybrids. 



Davenport (1908, p. 23) believes that the variability 

 in plumage color of canary-finch hybrids is entirely due 

 to the mottling factor" of the yellow canary. He says 

 (p. 23): 



It [the yellow canary] carries a mottling factor. Consequently 

 when the yellow canary is crossed with a pigmented canary or with a 

 finch the hybrids are mottled. 



In support of this hypothesis he makes the following 

 statement : 



That it is the yellow canary which contains the mottling factor 

 and is the source of the variability of the hybrids is shown by the 

 fact that (1) hybrids with the green canary do not vary in this 

 fashion, and (2) hybrids between any two species of finches— of 

 which many are bred by fanciers— are " cast in one mold." 



As regards the first of these two points, it may be said 

 that one should not expect canary-finch hybrids from a 

 ''green" (self-colored) canary to show yellow markings 

 as frequently as when a yellow canary is used. In regard 

 to the second point, Davenport (1908) seems to have 

 overlooked the fact that Blakston (1880?), on whose 

 authority this statement was probably based, states only 

 (p. 274) that all bullfinch-goldfinch "mules" are *'cast 

 in one mould." In fact one of Blakston 's (1880?) re- 



