154 Recent Literature. [zok 



tinctioiis very largely on the size and shape of the skull, A seasonal 

 change in the pelage was discovered to take place, which is another 

 factor tending to complicate the recognition of species and varieties. 



Owing to the close relationship existing between the species of the 

 genus Tamias, Mr. Allen concludes that they have been modified 

 from some comnion stock in comparatively recent times. He says: 

 ** Probably a more striking example of evolution by environment 

 cannot be cited-" Of the twenty-four forms which he recognizes, it 

 is possible that a few will, in the light of more ample material, be 

 reduced from specific to subspecific rank, as, for example, Tamias 

 amceniis; hut that any of the forms here considered will ever prove 

 to be mere individual variations is highly improbable. 



After a general review of the group, which occupies the first 



twenty-two pages, each species is taken up in detail, in which ; 



given the synonymy, habitat, technical descriptions of the pelage in 

 breeding season, in post-breeding season; and of the young; meas- 

 urements, a list of the specimens examined, and remarks on the 

 habits and characteristics of each species and on its relationship to 

 allied forms. Thus the whole ground is covered, and all that is 

 now known of our North American chipmunks is here to be found 

 in convenient and systematic shape. 



Eight species and varieties are ascribed to California alone. This 

 certainly seems like a very large number for so small an area, and 

 is to be accounted for only by the extreme variation in climate and 

 physical features of the different sections of the State. Some species, 

 which might at first sight appear to be mere varieties, overlap in 

 their range, and may easily be distinguished as distinct even when 

 taken from the same locality, thus proving their specific rank. This 

 is the case with mcrriami and speciosiis, and also with /r^/d^r and 

 anmnus, although in the latter case the differences are not so great, 

 and a larger series from neutral ground might show intergradation.' 



^ * ^x « X^ « 



The Ibis, ii, No. 7. On the Principal Modern Breeds of the 



W 



On a 



new Finch from Midway Island, North Pacific, by Scott B. Wilson 

 with colored plate of Tdcspiza cantans gen. et sp. nov. 



The Auk, vii, No. 3. Descriptions of a New Species and three 

 New Subspecies of Birds from Arizona, by Dr. Edgar A. Mearns. 



