( Ix ) 
variability and inheritance, the nature of the action of the 
environment, the effect of selection, etc., etc. This was a 
dream of the late Dr. Eomanes ; he has not lived to see 
it fulfilled, but if it should be realized in our time our 
entomologists will, I venture to hope, not be behind with 
suggested lines of work. 
If by way of comparison we now turn to that branch of 
the subject in which the empirical method has hitherto almost 
exclusively been employed, viz., the taxonomy of this same 
order Lepidoptera, the results are most instructive. In view 
of the immense body of facts, the number of named species 
and the mass of published descriptive matter, I do not think 
I shall be wrong if I say that the best energies of the acutest 
workers have been concentrated on this subject from the 
middle of the last century down to the present time. A 
record of nearly a century and a half against the thirty odd 
years that have elapsed since the introduction of the theoreti- 
cal method into the biological sciences. Is there any indi- 
cation that all this work has brought us nearer the " definite 
end " to which it was and is directed — the natural classifica- 
tion of the Lepidoptera — to an extent commensurate with 
the number of workers and the time bestowed upon it ? It 
is only quite recently that any decided advance has been made 
and that through the work of Hampson, Comstock, Chapman, 
Meyrick, and others. It cannot be said that we have been 
waiting all these years for materials — for a few thousand 
new species in one of the best " collected " groups in the 
whole world of insects in order that this sudden rush might 
be made. I take the view that we have been waiting rather 
for method than for additions to the lists of species ; that we 
have hitherto too much disregarded the spirit of the specula- 
tive method in our taxonomic work, and that we have now 
happily found a band of workers who refuse to submit to the 
plea of inability because all the existing species of Lepidoptera 
have not been collected and named. 
After advancing these arguments in favour of a more 
liberal use of the " scientific imagination " in connection with 
entomological subjects I feel it incumbent upon me to define 
the position a little more fully in order to prevent misunder- 
