22 INHERITANCE IN CANARIES. 



the hybrid, if at all, only where it is present in the goldfinch. Black, 

 on the other hand, is a color that belongs both to the wild canary and 

 the goldfinch. The yellow canary has merely lost one factor necessary 

 to the production of black in these situations where black occurs in the 

 green canary. When black is introduced by the goldfinch it is laid 

 down (1) in accordance with the goldfinch formula and (2) also in 

 accordance with the green canary formula, but (3) both distributions 

 are controlled by the variegation factor, so that black (like the other 

 pigments) is laid down only over more or less circumscribed areas of 

 the body. 



Series IV.— HYBRIDS BETWEEN THE YELLOW CANARY 

 AND OTHER SPECIES. 



Canary fanciers have been very activein making "mules" between 

 various species of finches. Besides the goldfinch, the linnet {Fringilla 

 Hnotd), the greenfinch {Fringilla chloris), and the siskin {Fringilla spinus) 

 have been crossed with the canary. 



The linnet is a prevailingly brown bird, with black, white-edged 

 quill feathers and darker striping on wing coverts and sides of body. 

 The hybrids with the yellow canary are said usually to be dark birds 

 resembling the linnet. Mottled birds sometimes occur, linnet colora- 

 tion showing in patches on the otherwise yellow background. (Blak- 

 ston, 1880, 272). Here the brown of the linnet seems to dominate over 

 the canary green, but the mottling factor of the yellow canary is active. 



The greenfinch is olive-green above, yellowish-green below, has 

 black remiges edged with yellow (forming a wing-bar) and black rec- 

 trices edged with olive-green, except the four outer tail feathers, which 

 are edged with bright yellow. The hybrids are sometimes dark like 

 the greenfinch, but " highly variegated" are common. Here, again, is 

 seen the mottling factor of the canary. 



The siskin is streaked greenish above anteriorly and yellowish 

 posteriorly; below is light green in the male and white in the female. 

 There is a yellow stripe over the eye. The sides of body and wing 

 coverts are distinctly striped. The wings and tail are prevailingly 

 black, but the base of the rectrices and a wing-bar and wing-bow are 

 yellow. The hybrid with the yellow canary (plate 1, fig. 2) closely 

 resembles the siskin — the dark beak, the yellow supraorbital stripe, 

 the striping, even to the lower tail-coverts, are all present. In my 

 hybrids the wing-coverts and rump are green as in the green canary. 

 Here again the hybrid shows the so-called reversion phenomena. 

 Mottling occurs in the hybrids under certain conditions, but the usual 

 type is all dark (plate 3, fig. 6). 



The foregoing descriptions show first that in all hybrids between 

 the yellow canary and a finch there is a tendency to "reversion" — a 



