2$ VJl oV 
W. B. 3. 
It should be constantly borne in mind that the Index is for 
future use, not for past or present use, and therefore that par¬ 
ticular combinations which some of us remember, will be unfamiliar 
to the great majority of those who use the Index. But even now, 
who can remember off hand the particular specific name with which 
all Qf-4 r hc ^subspecies of North American birds -are associated? In 
my own case, I think of subspecies as units , without regard to the 
combination,and in the case of a large number of western subspecies 
with which I have been for years familiar, I am obliged to admit 
that it is impossible for me to give the full combination off hand. 
Take a simple case. Suppose a man is in search of information 
respecting the Texas night hawk. He would naturally turn in the 
Index to Chordeiles texerisis under which head the bird was given 
in the first edition of our Checklist, and under which name any 
one would naturally think of it. But in the Index, if the full 
combinations are given, the name could not be found in its proper 
alphabetic order at all, but would occur on some distant page under 
the name Chordeiles acutipennis texensis . It must be remembered 
in this connection that the species and subspecies in our Index 
will not &© together in a single compact series, but will be sepa¬ 
rated by a vast accumulation of headings and subheadings relating 
to a great variety of subjects, so that the alphabetic position of 
a subspecific name will often vary several pages according to whe¬ 
ther it is indexed (as it should be in my judgment) under its indi ¬ 
vidual name , or whether - it is indexod under the species with which 
it chanced to be associated at the particular moment the last edi¬ 
tion or supplement of the Checklist happened to be voted upon. 
