28 
Canary Breeding 
Putting the reciprocal matings together we have 
Yellows - 101 Buffs = 66 
Proportion of yellows to buffs = almost exactly 3 : 2. 
„ males to females = 74 : 83. 
Douhle-yelloiv {yellow x yelloio) Matings. Number of Matings, 18. 
Progeny. 
Yellow Buff Unknown (whether yellow or huff) 
22 male 8 male 4 female 
26 female 8 female 
2 sex unknown 
50 16 4 
Proportion of yellows to buffs = 3:1 nearly, 
males to females = 30 : 38. 
From these tables it will be seen that the belief that more yellow progeny 
came from yellow male and buff female than from buff male and yellow female 
matings, is not substantiated. The proportion in both cases is almost exactly 3 : 2. 
It is further evident that double-yellowing practically doubles the number of 
yellows obtained, the proportion then being almost exactly 3:1, instead of 3 : 2. 
Females are rather more numerous than males in all the matings. 
The following birds are those in my muling strain which have produced most 
yellow progeny : 
(1) Variegated yellow % (bred from double-yellows) = 6 yellows — males and 
females. 
(2) Clear yellow ^ (bred from yellow ^ x buff %) = 2, cl. y. ^ + ^ cl. y. %. 
(3) Cinnamon ticked yellow % = b y. % +1 y. -¥^1 
(4) Ticked yellow $ (bred from a treble-yellowed (/" xm.b. %) = 5y. $ +ly. J'. 
(5) Variegated yellow cT (bred from double yellows) = 4 -f- 6 y. ? -H 2 6. </. 
The Effect of Double-yellowing. While double-yellow mating is thus shown to 
improve the colour of a strain, it must be done cautiously, as feather becomes thin 
and scanty, and the general health of the stock suffers if this method be used even 
for three or four generations in succession. It seems to be true that reciprocal 
yellow and buff matings should be the general rule, if the health of any strain is 
to be kept good. I have not been able, so far, to prove that any yellow, or any 
crested bird, was truly homozygous. The yellow quality of feather, like the crest, 
seems to be of a compound nature ; it is associated especially with thinness and 
scantiness of plumage, and results usually, if double-yellowing be continued to any 
extent, in a featherless condition of the body, especially on its under aspect. 
