BREEDING. 
323 
really commencing to sit in earnest, which last operation 
is only begun after the entire complement of eggs has 
been laid. 
Up to this time the inclination to sit has been increasing 
in intensity; it evinces itself in more ways than one. 
At the commencement of laying, the temperature of the 
bird’s blood rises, and this produces a restless feverish 
state of excitement, she utters peculiar notes and tones, 
eats but little, and casts many feathers from certain parts 
of the body, leaving bare places, which tend to facilitate 
the transmission of heat to the eggs. Many birds 
actually pluck the feathers from the necessary places 
and line the nest with them; some, the Grebes, for 
instance, swallow them instead. The bare skin now 
thickens, becomes wrinkled, heated, and of a reddish hue. 
With most birds these bare spots are on the centre of the 
lower portions of the breast and belly. In the Plovers, 
Guillemots, Razorbill, and Little Auk, they are situated on 
either side of the lower part of the belly; in the Kestrel 
they amount to three, one in the centre and one on each 
side of the lower part of the body. Some birds, like the 
Pigeons, Divers, Cormorants, &c., have none at all. These 
bare places are only found on the female, excepting in 
cases where the male assists the former in incubating, and 
singularly enough with those curious birds, the Plialaropes, 
they are found in the male alone. The size, and not 
the number of these patches, generally indicates the 
number of eggs; Gallinaceous birds possess only one patch, 
while the Razorbill has two. 
The duties of incubation rest principally with the mother, 
the male being but rarely engaged in this onerous business; 
in most cases he provides the female with food and 
gives her the benefit of his company, lightening the weary 
