216 THE CONDOR 
are undoubtedly what have given most peo- 
ple a wrong conception of systematic work 
in general, and of the so-called ‘“subspeci- 
fic’ races in particular. If the rank and 
file of bird students would put aside the 
idea that ‘‘microscopic”’ subdivisions of plas- 
tic species are made only for the purpose of 
bestowing new names, and think of the de- 
termined “subspecies” as admittedly short, 
but still definite steps along the evolution- 
ary highway, not only would the whole sci- 
ence of ornithology be benefited by a new 
interest, but we would be spared much of 
the ranting about “hair splitting’, in which 
well-meaning but misguided souls indulge 
from time to time. What constitutes a sub- 
species is just now a difficult question to 
answer. A composite opinion gained by 
personal conversation, and by perusal of 
current literature can be best expressed by, 
“Why is a hen?’ Some would use only a 
binomial for every recognizable form, others 
want to reduce to subspecific status all spe- 
cies bearing close resemblances to one an- 
other, and still others champion two kinds 
of subspecies! Obviously, the adoption of 
any of these extremes would work much 
harm, if for no other reason than that the 
true genetic relationships between most 
forms would not properly be expressed by 
the terms employed. 
Most conservative ornithologists advocate 
a middle course and believe that intergra- 
dation should be actually proven before re- 
ducing any form to subspecific status. But, 
what sort of intergradation? If we take 
into consideration all angles of the prob- 
lem, what can we possibly accept save that 
of geographic continuity,—an actual blood 
relationship? To designate as varieties geo- 
graphically isolated forms which have been 
completely segregated for thousands, per- 
haps tens of thousands of years from simi- 
lar organisms found in another area (or 
even on another continent!) simply because 
overlapping characters are shown by a few 
individuals is not telling the true story of 
conditions which now exist. True, there 
was undoubtedly one common ancestor; but 
so, for example, was there forall the grebes, 
or for all the gulls. If intergradation of all 
present-day species of grebes, or between 
any two of them were to be established 
through fossil remains—and this is not an 
impossible hypothesis—then, to be consist- 
ent, we should have now to regard them as 
subspecies! Intergradation through indi- 
vidual variation is inviting too many 
chances for error. As Grinnell (Auk, vol. 
37, 1921, p. 469) has pointed out, what as- 
Vol. XXIV 
Surance is there that young or subadults or 
even “sports” may not be used in attempt- 
ing to prove the point? 
The criteria of isolation for the use of 
the binomial and of actual blood fusion for 
use of the trinomial will, I believe, prove 
the ultimate ones to be adopted not only 
because they permit of more accuracy in 
allocation, but also because of the uniform- 
ity possible under their use. 
Yours very truly, 
A. J. VAN ROSsEM, 
Pasadena, California, July 14, 1922. 
LIFE HISTORIES OF NORTH AMERICAN BIRDS 
The Editor of The Condor: 
Realizing that no one man can know all 
there is to know about all the birds and 
that the completeness of the Life Histories 
of North American Birds depends on the co- 
Operation which the author receives from 
others, I wish to make this report of pro- 
gress and appeal to your readers for con- 
tributions, trusting that you will find the 
space to publish it at an early date. 
Two volumes have been published and 
the third, containing the Petrels and Peli- 
cans and their allies, is printed and should 
soon be out. The manuscript for the fourth 
volume, containing the Ducks, up to and in- 
cluding the Ring-necked Duck, is now in 
Washington in finished form and ready for 
publication. It is not too late to add to 
this, when I correct the galley proof, any 
notes of importance on habits or distribu- 
tion, and not too late to substitute any par- 
ticularly fine photographs for those that I 
have already selected. 
I am now at work on the fifth volume, 
which will contain the remainder of the 
Ducks and the Geese and Swans. I expect 
to finish this during the winter and send 
it to the publishers in the spring. The life 
histories are practically all written, subject 
to revision, but the photographs have not 
been selected. 
I have no notes on the courtship of the 
American and White-winged Scoters or of 
any of the Geese, except the Canada, or on 
any of the Swans or Tree Ducks. I have | 
no nesting photographs of Harlequin Duck, 
Barrow Golden-eye, any Geese except White- 
fronted and Canada, any Swans, or any 
Tree Ducks. I should be glad to receive 
contributions of notes or photographs to 
fill in any of these gaps. Or I should be 
glad to correspond with anyone who has 
anything else to offer. I am, of course,’ 
