550 COLOR AND GEOGRAPHICAL DISTRIBUTION OF BIRDS. 
1. Latitudinal and altitudinal variation in size of resident spe- 
cies; northern bred individuals, and those born at high eleva- 
tion, being larger than those born farther south or in the low 
lands 
2. Absolute increase of the size of the bill, even with diminu- 
tion in general bulk, in Florida birds, as compared with individ- 
uals of the same species born north of that peninsula: the same 
rule applying, to a less extent, to birds from Cape St. Lucas. 
3. Longer tails of western birds than of eastern examples of the 
same species. 
4. Darker color of birds from the Pacific coast than of specimens 
of the same species from the interior, ‘the latter frequently exhib- 
iting a bleached or weatherbeaten appearance, possibly the result 
of greater exposure to the elements, and less protection by dense 
forests.” 
Here then are three laws of climatic or regional variation in 
size and proportions, and two of color, in which Mr. Allen is 
anticipated by Professor Baird. But without going farther into 
the literature of the subject, I will proceed at once to discuss Mr. - 
Allen’s celebrated work published in 1871,* in order to show 
wherein he has anticipated me in the announcement of generaliza- 
tions, in cases illustrating them, or in reducing specific names to 
the rank of race, or “variety,” names. On p. 235, the law of in- 
creased intensity of color to the southward is announced, this not 
having been especially noted by previous writers (though Gloger 
says something indefinite in relation to it in his work above cited). 
This law, then, originates with Mr. Allen. The cases which he 
cites in illustration are the following: Quiscalus purpureus, Age 
laius pheeniceus, Ortyx Virginianus, Sturnella ‘‘Ludoviciana” (= 
magna), Galeoscoptes Carolinensis, Harporhynchus rufus, Centurus 
Carolinus, Picus pubescens, P. Gairdneri, Colaptes auratus, Thryo- 
thorus Ludovicianus, Troglodytes don, Geothlypis trichas, Pipilo 
erythropthalmus, Buteo lineatus and Bucephala Americana(!). The 
idea of “the so-called Bucephala Islandica being the larger northern 
type of B. Americana, in which the white markings on the head 
and wings occupy a somewhat larger area,” is entirely erro- 
neous, as every one acquainted with these very different species 
*Bulletin Mus. Comp. Zoöl., Cambridge, Mass., ii, 1871. P pyar On Individual = 
Geographical Variation among birds, consi ered te respect to its bearing upon 
186-250. 
