THE BRITISH NATURALIST. 



["August 



Poulton, and with equal care and patience. I apprehend that the 

 type form of A . betularia is still obtainable. The progeny of such a pair, 

 then, should be subjected, if necessary and possible, for successive 

 generations, to various influences, heat, cold, humidity, dryness, 

 obscured light, smoked glass, atmospheres adulterated with carbonic 

 acid, the larvae should be fed on stunted food, smoky or soot besprinked 

 leaves, in short, all the imaginable influences brought to bear on 

 them which the most active fancy might suppose at work in a state of 

 nature modified by civilization. 



Possibly this has been done, possibly there may be difficulties in 

 the way of which I am ignorant : perhaps this is a species which will 

 not feed in confinement. However that may be, such a method as 

 this would appear to my ignorance to be all singularly well calculated 

 to elicit valuable results. Without such experiments, and with very 

 insufficient and incomplete evidence as to the exact date of this 

 recent melanic tendency, its rate of increase and spheres of activity, 

 it appears to me that we are as yet hardly safe in coming to any 

 conclusion at all in the matter. 



In this, as in all other scientific enquiry, it seems to be most 

 essential for the attainment of what we are stipposed all to strive 

 after — the discover)' of truth — at all costs, to avoid that high a priori 

 road so fascinating and so treacherous, not to formulate a theory first 

 and then search out facts in its support, but rather to make sure of 

 facts first, leaving theories to evolve themselves, or be evolved with 

 deeper and wider experience. Thus is truth ultimately won ; no 

 conclusion at all is better than a wrong conclusion, and the progress 

 of human knowledge has been retarded by few things more than 

 the rashness, which, on insufficient evidence, leaps to a preconceived 

 assumption as to a proved certainty. 

 Lidsham, Cheshire. 



ENTOMOLOGICAL NOMENCLATURE. 



[A Reply to Dr. BucMl.) 

 BY C. W. DALE, F.E.S. 



Dr. Buckell puts me in mind of Van Tromp, the Dutchman, who 

 hoisted a broom at his mast-head, as a sign that he had swept the 

 Englishmen off the seas. He commences by accusing me of an 

 untruth. If he reads the "Young Naturalist," Vol. IX., p. 68, for the 

 year 1888, he will find the statement I have copied. He should also 

 read the following statement 1>\ Mr. W. F. Kirby, in the "Entom- 

 ologist's Monthly Magazine," Vol. VJ II., p. 42. — "The twelfth edition 

 of Linnaeus' " Systema Naturae " 1 i 767) is the date fixed by the rules 



