carries an abundance of soft material into the cavity, and forms a soft felt-like nest, in which the mother- 
bird lays her eggs and rears her young. Fine vegetable fibres, vegetable down, wool, moss, and fine, short 
hairs from various animals compose the bulk of the nest. Soft fur and downy feathers are also sometimes 
found in the lining. When a natural cavity is chosen the sight is often much too large and a great 
deal more material is demanded than when the builders do their own carpentry, but thp internal dimensions 
of the nest are always about the same. In shape the structure is globular or purse-like, from two and 
one-half to three inches in diameter, by from one and one-half to two and one-half deep externally. Within 
it measures about an inch and five-eighths each way. The mouth of the nest is usually contracted so 
that it measures from an inch and one-eighth to an inch and three-eighths. The diameter of the hole into 
the cavity is about an inch and one-eighth. 
EGGS : 
The complement of eggs varies from five to eight, six being probably the most frequent number. 
They measure in long-diameter from .58 to .65, and in short-diameter from ,47 to .52. A common size is 
about .48 x .60 of an inch. “North American Birds” gives the average size as .58 x .47. Maynard’s 
“Birds of North America” gives their dimensions as .45 to .50 in short-diameter, by .50 to .60 in long- 
diameter. Minot gives .50 x .63 as the average size. The ground-color of the shell is White. The markings 
consist of blotches, spots, and speckles of light reddish-brown; at times almost pure burnt sienna. Deep 
shell-marks are infrequent. 
DIFFERENTIAL POINTS: 
The nests of P. carolinensis and P. atricapillus are alike in materials of construction and size as well 
as in location. The eggs are also remarkably similar, yet a large series of each make apparent certain 
differences. The latter, according to eggs in my possession, average a little more in short-diameter, and 
a little less in long-diameter; this makes them the nearer spherical in shape. There are, however, a 
number of eggs of each which measure .48 x .60, or within .01 of this. The former contain not only the 
most marks, but they are upon the whole larger. The color is the same for each. I do. not believe it 
is possible to distinguish with certainty the nests and eggs of the two species. 
REMARKS : 
Plate LXVI represents a nest and three eggs of Parus atricapillus. The former was taken in 
Northern Ohio in 1885, the latter were selected from three sets, only one of which is from this State. 
The nest was three feet from the ground in a decayed stump, and the cavity was made by the Chickadees. 
It is composed entirely of moss and very fine downy fibres, the lining being similar to the exterior 
except that the fibres are more numerous within. For differences between the two species see page 228. 
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