ICTERID.E — THE ORIOLES. 157 



Mr. Nuttall* staies that if a Cow Blackbird's egg is deposited in a nest alone 

 it is uniformly forsaken, and lie also enumerates the Summer Yellowbird as 

 one of the nurses of the Cowbird. In both respects I think he is mistaken. 

 So far from forsaking her nest when one of these eggs is deposited, the Eed- 

 eyed Vireo has been known to commence incubation without having laid 

 any of her own eggs, and also to forsake her nest when the intrusive egg 

 has been taken and her own left. The D. mstiva, 1 think, invariably covers 

 up and destroys the Cowbird's eggs when deposited before lier own, and even 

 when deposited afterwards. 



The Cow Blackbird has no attractions as a singer, and has nothing that 

 deserves the name of song. His utterances are harsh and unmelodious. 



In September they begin to collect in large flocks, in localities favorable 

 for their sustenance. The Fresh Pond marshes in Cambridge were once 

 one of their chosen places of resort, in which they seemed to collect late in 

 September, as if coming from great distances. There they remained until 

 late in October, when they passed southward. 



Mr. Ridgway only met with this species in two places, the valley of the 

 Humboldt in September, and in June in the Truckee Valley. Their eggs 

 were also obtained in the Wahsatch Mountains, deposited in the nest of Pas- 

 serella 'schistacea, and in Bear Eiver Valley in the nest of Gcothlypis trichas. 



Mr. Boardman informs me that the Cow Blackbird is a very rare bird in 

 the neighborhood of Calais, Me., so much so that he does not see one of 

 these birds once in five years, even as a bird of passage. 



The eggs of this species are of a rounded oval, though some are more 

 oblong than others, and are nearly equally rounded at either end. They 

 vary from .85 of an inch to an inch in length, and from M) to .70 in breadth. 

 Their ground-color is white. In some it is so thickly covered with fine dot- 

 tings of ashy and purplish-brown that the ground is not distinguishable. In 

 others the egg is blotched with bold daslies of purple and wine-colored 

 brown. 



On the Rio Grande the eggs of the smaller southern race were found in 

 the nests of Vireo helli, and in each of the nests of the Vireo pusillus found 

 near Camp Grant, Arizona, there was an e^y of this species. At Caj)e St. 

 Lucas, Mr. Xantus found their eggs in nests of the PoUojitila mclanura. 

 We have no information in regard to their habits, and can only infer that 

 they must be substantially the same as those of the northern birds. 



The eggs of the var. obscurus exhibit a very marked variation in size from 

 those of the var. pecoris, and have a different appearance, though their colors 

 are nearly identical. Their ground-color is white, and their markings a 

 claret-brown. These markings are fewer, smaller, and less generally dis- 

 tributed, and the ground-color is much more apparent. They measure 

 .60 by .55 of an inch, and their capacity as compared with the eggs of the 

 pecoris is as 33 to 70, — a variation that is constant, and apparently too large 

 to be accounted for on climatic differences. 



