GEOGRAPHICAL DISTRIBUTION 363 
however, troubling ourselves on that score, or attempting a com- 
plete history of the subject since his treatment of it, it is proper to 
remark that Prof. Huxley pointed out (Proc. Zool. Soc. 1868, pp. 
313-319) that there was reason to divide the earth’s surface lati- 
tudinally, rather than longitudinally as Mr. Sclater had done, and 
that four primary Regions were better than stz—these four being: I. 
Arctogea, comprising Mr. Sclater’s Indian, Ethiopian, Palearctic, 
and Nearctic Regions; II. Austro-Columbia, corresponding with the 
Neotropical Region; III. Australasia; and IV. New Zealand—this 
last being cut off from that gentleman’s Australian Region. Eight 
years later, Mr. Wallace in his great work,! for which zoologists 
can never be too thankful, disregarding Prof. Huxley’s scheme, 
adopted with some very slight modifications the plans of Mr. 
Sclater, which had been already followed in the main by many 
others, and among them by the present writer in a contribution 
to the Encyclopedia Britannica. In the course, however, of com- 
piling that contribution a considerable number of doubts arose in 
his mind. Some of them he at the time intimated ; but it was not 
until several years after that he saw how the chiefest of them should 
be dispelled. The full force of Prof. Huxley’s reasoning is now 
evident to him, and he has to urge the recognition of New Zealand 
as a primary division, while the recent ornithological investigation 
of Alaska, shewing that it is peopled in summer by so many Passeres 
hitherto supposed to be of purely Palearctic type, has convinced 
him that Prof. Huxley’s statement of the Nearctic area being far 
more nearly allied to the Palearctic than to the Neotropical 
Region is not only true but has a still deeper meaning, for that it 
is impossible justifiably to separate the Palearctic and Nearctic 
areas as “Regions,” though we may keep the epithets as con- 
veniently indicating geographical portions of one enormous but 
continuous Region, to which the name WHolarctic may be fitly 
applied.2, Some rectification of the hitherto-accepted frontier of 
the Neotropical Region may thereby be required, but that is a 
comparatively unimportant consideration, and it is not proposed 
1 The Geographical Distribution of Animals. 2 vols. London: 1876. My 
own gratitude to the author for allowing me at a critical time tosee the manu- 
script of this work prior to its publication has been before expressed (Lncyclop. 
Brit, ed. 9, iii. p. 737); but will never be forgotten. 
2 I have to thank Prof. Heilprin, who had originally (Proc. Ac. Philad. 
1882, p. 334) bestowed the name ‘‘Triarctic ” on this combination, for so readily 
adopting (Nature, xxvii. p. 606) my suggestion to call it ‘‘ Holarctic,” under 
which name it appears in the excellent defence of his position (Proc. Ac. Philad. 
1883, pp. 266-275) as well as in his work (The Geographical and Geological 
Distribution of Animals. New York: 1887). The objections raised to this 
combination by Mr. Wallace and Dr. Gill will be found in Nature (xxvii. 
p. 482, xxviii. p. 124). 
