1893.] Evolution in the Genus Megascops. ` 533 
“Great as are the differences between the breeds of the pig- 
eon, I am fully convinced that the common opinion of natu- 
ralists is correct, namely, that all are descended from the rock 
pigeon, Columba livia * * * * The rock pigeon 
is of a slaty blue with white loins, * * The tail has a 
terminal dark bar, with the outer feathers externally edged at 
the base with white. The wings have two black bars. * * 
Now in every one of the domestic breeds, taking thoroughly 
well bred birds, all the above marks, even to the white edging 
of the outer tail feathers, sometimes occur perfectly developed. 
Moreover, when birds belonging to two or more distinct breeds 
are crossed, none of which are blue or have any of the speci- 
fied marks, the mongrel offspring are very apt suddenly to 
acquire these characters.” (If this be true of distinct species, 
how much more isit true of different color phases of the same 
species). “To give one instance out of several I have 
observed: I crossed some white fantails, which breed very true, 
with some black barbs—and it so happens that blue varieties 
‘of barbs are so rare that I never heard of an instance in Eng- 
land, and the mongrels were black brown and mottled. I also 
crossed a barb with a spot, which is a white bird with red tail 
and red spot on the forehead, and which notoriously breeds 
very true; the mongrels were dusky and mottled. I then 
crossed one of the mongrel barb-fantails with a mongrel barb- 
spot, and they produced a bird of as beautiful a blue color, 
with the white loins, double black wing bar, and barred and 
-white edged tail feathers, as any wild rock pigeon! We can 
understand these facts, on the well known principle of rever- 
sion to ancestral characters, if all the domestic breeds are 
descended from the rock pigeon.” 
Now if this reversion to ancestral characters occurs in breeds 
so far removed from the parent stock and from each other— 
how much more is it reasonable to suppose that a color phase 
of the screech owl, when found continually producing gray 
birds, while gray birds produce grays alone—is but a repeti- 
tion only between birds more closely related, of the same per- 
formance? 
: (To be continued.) 
