1896 | BOTANICAL OPPORTUNITY 213 
to the principal literature of any subject in which he chanced to 
be interested. Perhaps as library facilities accumulate at the 
great centers of research, some method may be found of sup- 
plementing them with the skill of expert librarians who shall 
be able and willing to carry the contents of the library, at least 
in skeleton form, to those who cannot come to it; but the time 
has hardly yet come when any American library is complete 
enough in all branches to offer this aid with a reasonable chance 
of doing what it promises, or so manned as to make such assist- 
ance possible except at the sacrifice of more valuable direct 
research. 
For the present, then, the investigator must be content to do 
his own delving into the literature of his predecessors. Fortu- 
nately, much of the earlier literature has been sought out by 
some of the writers on any branch that has been the subject of 
earlier study, so that, starting with a memoir of recent date, one 
is guided to others, each of which may bring further references, 
until, if he have access to the works, almost the entire earlier 
literature is unearthed. On the other hand, the most recent 
literature of a subject is always the most difficult to find and 
use. After a study has been gotten well under way, so that the 
Student is keenly alert to every observation or published item in 
any way bearing on it, if he have access to a library receiving 
the principal current journals he is not likely to overlook any 
'Mportant publication on his specialty which then appears. As 
a tule, all of the larger papers, at least, are noticed in Just’s 
Jahresbericht, generally not more than a year later than that for 
which the volume purports to be compiled ; but as the /ahres- 
bericht is always some three years in arrears it is difficult to pre- 
vent notes extending over a period of this duration from being 
defective, at least for the earlier part of the time, and there is 
at present no means of removing this difficulty, though the plan 
Proposed to zoologists a year ago, and, I suppose, tested during 
8 present season, if successful would be equally applicable to 
any, 
So far as the final result is concerned, perhaps the manner in 
