most nests; still, the old habit is so powerful that nests are seldom built without it, though the quan- 
tity is often very limited. The cavity is thickly lined with fine fibres, slender grasses, dead moss, and 
horse-hairs, the circular arrangement of which, especially about the rim, forms a striking contrast to the 
jumbled appearance of the foundation and superstructure; occasionally, feathers, wool, and plant-down 
are used in the lining. The mud, besides giving form and solidity to the structure, is the stucco which 
holds it to its support. Some nests built upon horizontal surfaces in protected spots, have very little 
mud in their composition, and this is principally about the base. The diameter of the cavity at the 
rim averages about two and one-half inches ; its depth, about one and one-half inches. The external 
dimensions of a nest built against a perpendicular wall are as follows: Distance across the widest part 
of the flattened side, five and one-quarter inches ; distance from the rim to the lowest point, five and 
one-quarter inches. The diameter of the base of a nest taken from a shelving-rock is five and one-half 
inches ; depth, four and one-lialf inches ; width at top, three and three-fourths inches. 
EGGS: 
The complement of eggs is usually five. The shell is white, with a very faint creamy-tint; some- 
times it is marked about the crown with a few reddish-brown specks or spots. I have several times 
found nests containing one or two such eggs, the remainder being normal. They average in size .74 x 
.57 of an inch; from this they rarely vary more than .05 of an inch. 
DIFFERENTIAL POINTS : 
The eggs can usually be identified by careful measurements and attention to the curve of the out- 
line, together with the tint of the shell. The eggs of the White-bellied Swallow, Rough-winged Swallow, 
and the white eggs of the Indigobird resemble them somewhat. The nest cannot easily be mistaken for 
the work of any other bird. 
REMARKS : 
The nest represented by Plate X was built early in May, against an inch plank, used as a brace 
between the timbers of a wooden culvert, about four feet above the surface of the run. It contained 
five fresh eggs. The road passing over the bridge was much traveled, but the clatter of horses’ hoofs 
and rattle of wagons, though loud and frightful to a person beneath, did not seem to annoy the birds, 
which, judging from the various marks of former nests, had occupied the place for a number of years. 
Attachment to the nesting locality is more or less manifested by all our birds, but in none is it 
stronger than in the Pewee. Throughout their lives, if circumstances are favorable, the same pair will 
return every spring to their first nesting-spot, and sometimes even bring with them their offspring, to 
build in the immediate neighborhood of their birth-place. This habit endears them to the country 
people — in fact, to all who are acquainted with the bird — and “the nest on the porch pillar” is as 
studiously guarded as if an unfailing omen of good luck. 
Semi-domestication is beginning to tell upon the nest of this species, as it has already done upon 
some others. Now and then, a structure is found in which no mud at all is used. I have seen one, 
taken from a beam of a shed, in which no earth was employed, for, not exposed to wind or rain, it was 
sufficiently strong without it. It is not impossible that, in time, the mud may be entirely discarded, and, 
instead of the clay-house, with its beautiful moss-covei'ed walls, will be seen simply a nest of grasses 
and fibres in some well-protected place about the dwelling of man. 
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