The Problems of Ecology. 199 
vegetation of an area as we actually see it, gives no doubt ample 
opportunity for the waste of time over recording details of trifling 
importance, and this danger is all the greater because the higher 
scientific development of the subject is still in such a rudimentary 
condition that we are frequently quite in the dark as to what is of 
importance and what is not. The danger I have thus briefly 
touched upon has not been without its exemplification in some of the 
work that has been published, and has been responsible for much of 
the distrust of ecological work to which reference was made at the 
outset. 
Another type of criticism which has been made, though super¬ 
ficially plausible, is I venture to think largely due to misapprehension. 
It has been objected that' the straight-forward mapping of the 
vegetation of an area without the previous formulation of definite 
problems for solution is a mistaken and unscientific procedure. I 
have already attempted to shew that it is, on the contrary, a 
legitimate and necessary part of our attempt to become completely 
acquainted with the vegetation of the world, and that if we neglect 
it and content ourselves with the floristic system we obtain a one¬ 
sided and misleading knowledge. Till a certain number of accurately 
observed facts reveal themselves we cannot possibly formulate 
problems. There can be no problems in comparative anatomy till 
we know the structure of a certain number of organisms, nor in 
stratigraphical geology till we know the distribution and succession 
of a certain number of rocks. And similarly there cannot be 
problems in the study of plant-associations till we know the nature 
and distribution of the associations in question. The problems 
arise, and are arising, fast enough as the facts are ascertained. 
And that must be so in all branches of science. We must remember 
that the systematic study of ecology is no more advanced than 
plant-anatomy was in the time of Von Mohl, or geology before 
Lyell, Sedgwick and Murchison; though no doubt it differs from 
these subjects in being a kind of synthesis of several branches of 
science, rather than a new branch having to develop from the 
ground. It is possible, of course, to go on aimlessly piling up facts 
with little thought of what they may mean. It is possible to adopt 
a method unsuitable for the region chosen and thus fail to obtain 
satisfactory results. But these are dangers not peculiar to ecology, 
but rather to the unintelligent pursuit of any branch of knowledge. 
On what I have called the second stage of ecological work, the 
experimental enquiry into the complex relations obtaining between 
the plants making up an association and their environment, there 
is no space to enlarge. Starting points for such enquiries are 
