3792 The Zoologist — December, 1873. 



regarding climatic variations in colour and proportions. The 

 generalizations advanced in this paper are the following : — 



1. Latitudinal and altitudinal variation in size of resident 

 species; northern bred individuals, and those born at high eleva- 

 tion, being larger than those born further south or in the low lands. 



2. Absolute increase of the size of the bill, even with diminution 

 in general bulk, in Florida birds, as compared with individuals 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 colour of birds from the Pacific coast than of speci- 

 mens of the same species from the interior, "the latter frequently 

 exhibiting a bleached or weather-beaten 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 colour, in which Mr. Allen is antici- 

 pated 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 

 increased intensity of colour 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 pur- 

 pureas, Agelaius phacniceus, Ortyx Virginianus, Sturuella " Ludo- 

 viciana" (= magna), G^lcoscoptcs Carolinensis, Harporhynchus 

 rufus, Centurus Carolinus, Picus pubescens, P. Gairdneri, Colaptes 

 auratus, Thryothorus Ludovicianus, Troglodytes aedon, Geothlypis 

 trichas, Pipilo erythropthalraus, 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," 



* 'Bulletin Mus. Comp. Zool.,' Cambridge, Mass., il. 1871. Tart III. "On 

 Individual and Geograpbical Yariation among Birds, considered in respect to its 

 bearing upon the Value of certain assumed Specific Characters," pp. lyG— 350. 



