haracterised in Moore's time, in 1735. Mr.
Brent says that two varieties exist, which differ in size.

RACE XI.--_Scarcely differing in structure from the wild Columba livia._

_Sub-race 1. Laughers. Size less than the Rock-pigeon; voice very
peculiar._--As this bird agrees in nearly all its proportions with the
rock-pigeon, though of smaller size, I should not have thought it
worthy of mention, had it not been for its peculiar voice--a character
supposed seldom to vary with birds. Although the voice of the Laugher
is very different from that of the Trumpeter, yet one of my Trumpeters
used to utter a single note like that of the Laugher. I have kept two
varieties of Laughers, which differed only in one variety being
turn-crowned; the smooth-headed kind, for which I am indebted to the
kindness of Mr. Brent, besides its peculiar note, used to coo in a
singular and pleasing manner, which, independently, struck both Mr.
Brent and myself as resembling that of the turtle-dove. Both varieties
come from Arabia. This breed was known by Moore in 1735. A pigeon which
seems to say Yak-roo is mentioned in 1600 in the 'Ayeen Akbery,' and is
probably the same breed. Sir W. Elliot has also sent me from Madras a
pigeon called Yahui, said to have come from Mecca, which does not
differ in appearance from the Laugher; it has "a deep melancholy voice,
like Yahu, often repeated." Yahu, yahu, means Oh God, Oh God; and
Sayzid Mohammed Musari, in the treatise written about 100 years ago,
says that these birds "are not flown, because they repeat the name of
the Most High God." Mr. Keith Abbott, however, informs me that the
common pigeon is called Yahoo in Persia.

_Sub-race II. Common Frill-back_ (Die Strupp-Taube). _Beak rather
longer than in the Rock-pigeon; feathers reversed._--This is a
considerably larger bird than the rock-pigeons and with the beak,
proportionally with the size of body, a little (viz. by .04 of an inch)
longer. The feathers, especially on the wing-coverts, have their points
curled upwards or backwards.

_Sub-race III. Nuns_ (Pigeons-coquilles).--These elegant birds are
smaller than the rock-pigeon. The beak is actually .17, and
proportionally with the size of the body .1 of an inch shorter than in
the rock-pigeons, although of the same thickness. In young birds the
scutellae on the tarsi