SOUTHERN ARIZONA 229 



rivalled song from some point of vantage on the 

 face of every precipice. 



I have spoken of the humming-birds, but per- 

 haps have not given an adequate idea of their 

 abundance. A kind of thistle that bloomed at 

 midsummer on the hillsides in patches was 

 thronged by these tiny jewels. There were eight 

 kinds present in incredible numbers, and these 

 were represented during midsummer in every stage 

 of plumage. 



The gray vireo, heretofore known by but few 

 specimens, was very abundant, and bred com- 

 monly. For a paper in regard to the breeding 

 habits of this bird, together with notes in respect 

 to its marked tameness, the reader is referred to 

 the appended bibliography. The least vireo was 

 a common visitor and summer resident, and the 

 plumbeous vireo, as well as the western warbling 

 vireo, was plentiful, while Cassin's vireo also was 

 observed as a migrant. The Phai'nopepla retired 

 to lower altitudes in the winter, but many bred 

 here; and again reference is made to the bibli- 

 ography. The purple martin, cliff, barn, and violet 

 green swallows were present in numbers in their 

 season ; while the tree-swallow, the rough-winged 

 swallow, and the bank-swallow were little more than 

 casual. The white-throated swift migrated in large 

 companies, and sometimes appeared during winter. 

 Vaux's swift was met with on a single occasion. 



