II.—By P. St. M. PopMor#, M.A., F.R.G.S. 
Note on the Fertility of Woodpigeon Hybrids. 
HE Ringdove’s swift flight and extraordinary powers of endurance suggested to 
my mind years ago the possibility of cross-breeding with long-distance Homers. 
I made many fruitless attempts to 
breed hybrids with C. paluwmbus cock. At 
one time I had half-a-dozen pairs thus 
mated, but no eggs proved fertile. 
Professor A. Newton, writing to 
me on this subject, says: “The fruition 
of hybrids in zoology is exactly on ‘all 
fours’ with that of hybrids in botany. 
Between some species of animals, as the 
Equide, the hybrids appear to be abso- 
lutely sterile, and in the Bovide they are 
fertile. Just the same thing is observed 
(so botanists say) among plants. Again, 
among plants there are species in which it 
seems easy to get a hybrid between the 
male of A and the female of B, but the 
reciprocal cross between the male of B and 
the female of A is almost or quite impossible. 
I am told that ‘fanciers’ who breed mule 
birds find exactly the same thing.” 
The importance of genuine hybridisa- 
tion is hardly less valuable to science than 
the discovery that associated the Colym- 
boides with the Colymbide, and traced the 
first Columba to the lower Miocene beds 
of Alher and Puy de Dome. 
During the past fifteen years I have 
bred hybrids from C. palwmbus, -C. e@nas, 
C. turtur, ete. From 1897 to 1899 I 
hatched fifty hybrids, but all died just 
before fledging. 
On August 22nd, 1899, I wrote: 
“ Hileven days appear to be the limit of life 
permitted to ringdove hybrids. The young 
invariably died on the eleventh or fifth day.” 
It was not until September, 1899, that 
I successfully reared a ringdove hybrid. 
This bird has proved rentarkably strong 
and healthy. He has twice crossed the WOUNG. on aaeTy NGS ea 
Atlantic and survived the extremes of (C. palumbus and CO. domesticus) and (C. Livia). 
heat and cold during exhibition. 
The ringdove hybrid, when six months old, paired to a hen Dragoon. The eggs 
were not fertile until May 22nd, 1902. 
This year I have reared two fine birds from this strange crossing, and a glance 
at the illustrations will convince anyone of the success of my experiment. The birds 
are remarkable for the length of the flight feathers and strength of wing. 
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