364 PIGEONS AND SAND-GROUSE. 
example of which we may mention the performances of the carrier-pigeons. AlI 
pigeons are provided with a large crop, which becomes glandular during the breeding- 
season, and then secretes a milky fluid to moisten the half-digested food on which 
the young are nourished. The amount of food which a pigeon can consume in a day 
is almost incredible, it being 
probable that one of these 
birds is capable of eating a 
quantity more than equal its 
own weight. Like the sand- 
grouse, pigeons drink by 
thrusting the bill into the 
water and retaining it there 
till they have quenched their 
thirst. All pigeons pair for 
life, and both sexes take part 

UPPER PORTION OF THE RIGHT HUMERUS OF (a) SAND-GROUSE, 
(b) FOWL, AND (c) PIGEON, in the building of the nest, 
(From Garrod, Proc. Zool, Soc., 1874.) incubation, and rearing of the 
young. When hatched, the 
latter are naked and helpless, and thus need care from both parents. The bill of 
the young is larger and more fleshy than that of the adult, and during the operation 
of feeding, the old bird thrusts its beak inside that of its offspring, and injects the 
semi-liquid nutriment. The nest is a simple structure composed of twigs, and 
generally placed in a tree; the eggs never more than two in number, being invari- 
ably pure white. 
THE GREEN, PAINTED, AND FRUIT-PIGEONS. 
Family TRERONIDZ. 
This family contains a large number of arboreal species inhabiting Africa, 
South-Eastern Asia, and the islands of the Eastern Archipelago generally, distin- 
guished by their rather short legs, which are feathered for more than half their 
length, and are usually shorter than the middle toe and claw; the soles of the feet 
being very broad, and the skin of each toe expanded on the sides. Of these birds 
three subfamilies may be distinguished, the first containing the green pigeons, which 
have the bill rather thick. The plumage, with a few exceptions, in which it is 
chocolate-brown, is mostly green, and most species have a yellow band across the 
wings. In the first three genera the base of the bill is soft, and the sheath of 
the upper mandible does not reach the feathers of the forehead. 
Wedge-Tailed The wedge-tailed green pigeons (Sphenocercus) include seven 
Green Pigeons. (ifferent species, with wedge-shaped tails, and the middle feathers 
more or less pointed, from South-Eastern Asia; the best known being the Himalayan 
and Burmese forms (S. apicicauda and SN. sphenurus). The former is distinguished 
by having the under surface of the tail black, with a broad grey band across the 
extremity, and the middle pair of tail-feathers long and pointed ; while in the latter 
the under surface of the tail is uniform grey, and the middle pair of feathers are 
less pointed and much shorter. The habits of this and the other green pigeons are 
