yan; 1919 
ern hemisphere. “. . . Migration is sim- 
ply an exodus, followed by a return move- 
ment to breeding grounds.” “. . . Bird 
migration is the adjustment of the bird pop- 
ulation of the world to the seasons . ; 
the evolution of the seasons being the re- 
mote cause of bird migration.’ The more 
speculative portion of Loomis’s paper, for 
example as to how migrating birds find their 
way, are stimulative, and will always need 
to be taken account of by future students in 
the field, but they leave the reader in dark- 
ness at many turns. We note, in this con- 
nection, that John B. Watson’s conclusions 
are discounted. Loomis can see no good rea- 
son for ascribing to birds a sixth sense by 
which they can find their way. They are 
guided solely, in his opinion, by ordinary 
faculties intensified, plus an “innate desire 
to travel.” An admittedly weak place in 
this guidance theory concerns the return- 
migration of birds nesting on remote oceanic 
islands. 
The detailed descriptions of molts and 
plumages, based in many cases upon long se- 
ries of specimens, constitute perhaps the 
most important feature of the paper. We 
are quite convinced that Loomis is right in 
placing in synonymy a number of names, the 
original characterizations accompanying the 
proposal of which include only points of col- 
or just such as is demonstrated in available 
material to be due to age, fading, or loss of 
“bloom”. No one who in the future attempts 
to deal systematically with the Tubinares 
can allow himself to overlook these import- 
ant factors; and to become thoroughly famil- 
iar with them requires a great amount of 
close study and an exercise of mature judg: 
ment. 
In this connection, Loomis lays great 
stress on what appears to him to be in this 
order of birds a relatively very common 
state of double coloration, or ‘“‘dichromat- 
ism”. In certain cases he is inclined to look 
upon dichromatism as subject to geographic 
factors, so that a light phase of a given spe- 
cies might predominate or occur exclusively 
in one area, and a dark phase of the same 
species in another. Here we are tempted to 
believe that the dichromatism idea has be- 
come confused with that of true geographic 
variation, the latter leading to the origin of 
new species. Dichromatism undoubtedly 
does exist in certain tubinarine birds, but 
there is a chance that Loomis has inferred 
its existence in cases where adequate ma- 
terial is still lacking to completely establish 
the fact. 
PUBLICATIONS REVIEWED 45 
Mr. Loomis’s special method of handling 
geographic variation leads him to place uun- 
der the synonymy of Oceanodroma leucorhoa 
no less than five current names of petrels, 
namely socorroensis, kaedingi, monorhis, 
beldingi, and beali. This case illustrates his 
tenet that “the subspecies theory” is “dis- 
carded as a theory that has outlived its use- 
fulness.” In other words only full species are 
given systematic recognition, the criterion of 
intergradation, as here specially applied, 
serving as the basis of exclusion. Geographic 
variation is handled as of coordinate import- 
ance with age, sexual and seasonal varia- 
tion. It is as if the process of evolution 
itself had been denied! 
On the other hand we cannot but heartily 
commend Loomis’s conservative stand in re- 
gard to the recognition of genera. The fu- 
tility of repeated subdivision of genera down 
to the only logical limit, the one-species ge- 
nus, is well set forth. There can in our 
mind be little well-grounded defense of the 
principle lately put into practice by Mathews 
and others whereby it is concluded that two 
species occupying the same area must ipso 
facto belong to two separate genera. 
Cooper’s California record of the Yellow- 
nosed Albatross (Thalassogeron culminatus ) 
on the basis of a skull found on the sea- 
beach near San Francisco is corroborated by 
Mr. Loomis. The skull, with bill largely in- 
tact, was carefully examined previous to its 
destruction in the fire of 1906. The species 
thus becomes re-instated on our regular list 
of California birds, it having heretofore re- 
posed among the hypotheticals. Cooper's 
record of the Giant Fulmar from Monterey 
is not, however, credited. 
Several tubinarine birds are recorded 
from the high seas some hundreds of miles 
off the coast of California whose names do 
not appear on our state list nor even on the 
North American list. Of course the limits 
of a state with a sea coast can only be set at 
a greater or less distance offshore in arbi- 
trary fashion, but it would seem to the un- 
dersigned that they should not extend be- 
yond say one hundred miles outside the 
headlands or outermost islands. It is per- 
haps a somewhat different matter as regards 
inclusion in the North American list. 
The care displayed throughout in gram- 
matical construction, spelling and final 
proof-reading, has resulted in a production 
well-nigh above criticism from these stand- 
points. Indeed, it may be stated with some 
assurance that no ornithological paper has 
appeared in years so free from typographical 
