500 SwARTH, California Forms of Psaltriparus. [oct' 



inevitably suggests problems and questions to be answered only by 

 means of extensive series from other points. My conclusions as 

 herein stated refer only to the California forms of Psaltriparus — 

 P. minimus minimus, P. minimus calif ornicus, and P. plumbeus. 

 Of the subspecies P. minimus saturatus, from the Puget Sound 

 region (not included in the A. 0. U. Check-List), the specimens at 

 hand are too few in number to justify any expression of opinion. 

 Of the Lower California form, P. minimum grindce, no skins were 

 examined. Neither did I have examples of any form of P. mclano- 

 tis, and although the variations of this last mentioned species would 

 seem to have little or no bearing upon any California problem, yet 

 the relationships of viclanotis to plumbeus, and of plumbeus to mini- 

 mus, are such that only a general survey of the whole group, based 

 upon at least as much and as satisfactory material from all regions 

 as has been available from parts of California, could serve to explain 

 certain of the questions that have arisen. 



In the conclusions at which I have arrived I have been influenced 

 throughout by one belief, a fact sometimes questioned, but ol the 

 truth of which both observation in the field, and the study of 

 specimens, has convinced me. This is, that the various species of 

 bush-tits, at least in California and Arizona, are absolutely resident 

 wherever found. Lender this conviction I have sought to explain 

 every observed variation in specimens on any grounds other than 

 that of the migration of one form into the habitat of another. 



Perhaps it may be worth while to detail some of the evidence on 

 which this belief is based. Some years ago I published (Swarth,. 

 1900, pp. 14-16, 37-41) a list of birds observed at a point near Los 

 Angeles, California. Of the one hundred and seventy-five species 

 included therein only a small fraction were breeders, the bulk of 

 the list being composed of migrants. Obviously this place was in 

 an extensively used migration path. In many years' observation, 

 continued long after this paper was published, but one solitary 

 bush-tit was seen at this station, though some three miles to the 

 northward, and perhaps a little farther southward, the species is 

 locally a most abundant resident. 



In all my experience I have never seen bush-tits in flight sugges- 

 tive of migration. On the Berkeley campus, as one favorable place 

 of observation, it seemed apparent that the same flocks of birds in 



