and there that a bit of hornet's nest and grass can be seen. The superstructure is composed principally 

 of wide blades of soft grass; the lining is similar to No. 1. 



]N"o. 4. Collected June 1, 1877 ; contained two fresh eggs ; situated about fifteen feet from the ground 

 in a horizontal forlv of a water maple, on the bank of a creek. Internal diameter, two and one-half; 

 internal depth, two and five-eighths; external diameter, three; external depth, two and one fourth inches. 

 Externally it is composed of flaxen fibres, strips of bark, and chips of rotten wood. The superstructure 

 and lining are similar to No. 1, but of a lighter shade. There is no web or silk about the structure. 



Nests before me, built in towns, contain, besides the materials mentioned above, paper, threads, ravel- 

 ings, and bits of cloth. The average size of the nest is about two inches in internal diameter; one and 

 five-eighths in internal depth; two and three-fourths in external diameter; and two and a fourth in 

 external depth. The widest part of the nest is usually at the rim. 



EGGS : 



The number of eggs in a set varies from three to five. They are pure white, spotted and speckled, 

 principally about the base, with chocolate-brown of different shades, at times so dark as to appear 

 almost black; occasionally very fine, wavy lines are added to these marks. Rarely an egg is almost 

 immaculate; deep shell marks are yellowish-brown. In long-diameter they. measure from .75 to .95; in 

 short-diameter, from .52 to .66. A set of four eggs before me, of about the average size, measure 

 respectively, .80 x .60, .81 x .59, .79 x .60, and .80 x .60. A set of four eggs in the possession of Mr. 

 Dury, average .90 x .54. 



DIFFERENTIAL POINTS: 

 See Vireo gilvus. 



REMARKS : 



The nest illustrated was taken the second of June, 1880, It was situated at the extremity of an 

 oak branch, seven feet from the ground. The exterior is composed of pieces of hornet's nest, strips of 

 inner bark of trees and plants, shreds of the inner bark of the wild grape-vine, and bits of web. The 

 hornet-paper is bound tightly with flaxen shreds, frequently a stitch is taken in it, as shown in the 

 large piece in front. The interior is composed entirely of long shreds of the inner bark of the grape- 

 vine. The two eggs figured show the average in size, shape, and markings. 



The external measurements given for this nest as Avell as for that of the Warbling Vireo, are a 

 little less than those given by eastern writers for the same species. The internal measurements are, 

 however, the same. It seems probable, therefore, that less material is used by these birds in the con- 

 struction of their nests in the West than in the East. It may, however, be entirely accidental that I 

 have met with none over three inches in external diameter. 



The Cowbird frequently selects this Vireo's nest in which to deposit her eggs. Sometimes thev are 

 hatched with apparent indifference, and, sometimes, the nest will be deserted on this account. Several 

 years ago I found a deserted nest containing three Cowbird's eggs. The same season I discovered 

 another containing two Cowbird's eggs and three Vireo's, all partly incubated. Recently, while examinino- 

 the materials of a nest, a dull po}) was heard to come from the bottom of the structure. Investigation 

 showed the cause of the noise to be the bursting of an addled Cowbird's egg concealed between the 

 foundation and lining. It had evidently been deposited before the nest was completed. Mr. Dury men- 

 tions an instance which came under his notice, where the parasitical egg was disposed of by placino- a 

 new lining in the nest. The Cowbird, not discouraged by this performance, laid another egg. At this the 

 Vireo became disgusted, and abandoned the nest, notwithstanding she had deposited two of her eo-o-s 



96 



