( liii ) 
vance of Nature, without making any attempt to generalise 
the facts so acquired," as *'a mere amusement, fascinating 
indeed, and even useful, but totally disconnected with the 
objects of philosophic science." Now I venture to think that 
entomology in this country has been retarded in its develop- 
ment for want of a little more of this *' philosophic science " ; 
by an unwillingness on the part of our most active workers 
to give rein to the imagination — by an overcautiousness 
which is damping to the speculative faculty. There are no 
doubt many present who will not agree with this view, but I 
claim indulgence while I state my case in its support. It 
will, I think, be conceded that we have passed beyond the 
mere fact-collecting stage. It appears to me that in ento- 
mology we have arrived at a state where we are suffering 
from a plethora of facts ; if we are not in a position to 
explain everything connected with the development, life- 
histories, instincts, classification and distribution of insects 
as a class of animals, we are at any rate in a position, 
speaking paradoxically, to know what we want to know, and 
I do not see how we are going to advance unless a more 
generous use is made of hypothesis as a scientific guide. It 
is this point which I desire to urge and to show that there is 
no real danger in boldly facing what the late Dr. Eomanes 
aptly calls the bugbear speculation. 
In the first place, with respect to the physical sciences, 
there is abundant justification for the view which I am 
advocating. We have there long ceased to collect random 
facts ; observations and experiments are suggested by 
hypothesis. That prince among experimental philosophers, 
Michael Faraday, was wont to say: "Let us encourage 
ourselves by a little more imagination prior to experiment." 
The state of affairs is well summed up in one of the latest 
works on chemistry in which the author in introducing the 
fundamental principles of modern investigation says : — 
" The history of the exact sciences teaches us that we may 
discover new laws of Nature in two essentially different ways, 
one of which may be designated as the empirical, the other 
as the theoretical. Thus in one way by suitable observa- 
tions, one collects abundant material ..... and then by a 
