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PIGEONS AND SAND-GROUSE. 
which may be divided into six subgenera, founded on the general colour of the 
plumage and the shape of the flight-feathers. It will be sufficient to mention one 
or two species in which the general colour is mostly metallic on the upper-parts, 
the tail uniform in colour, and the flight-feathers normal in shape. In the nutmeg- 
pigeon (0. cenea), common in the Indo-Burmese countries, Ceylon, and the Andamans, 
the head, neck, and under-parts of the body are grey, the upper-parts bronze-green, 
MADAGASCAR WART-PIGEONS (f nat. Size). 
and the under tail-coverts deep chestnut. This bird keeps to the larger forest 
trees, and lives on fruit, especially the wild nutmeg, which it swallows whole, 
although only the mace is digested, the nutmeg being disgorged. Another closely 
allied species, the Nicobar nutmeg-pigeon ( C. insularis), of the islands from whence 
it derives its name, differs in having the under tail-coverts mixed with dark green. 
In the Nicobars it occurs singly, in pairs, or in small parties; and its deep low coo 
may be heard all day resounding through the forest. It breeds in February and 
March, and its nest has been found in a cocoanut-palm about twenty feet from the 
