THE ENTOMOLOGIST. 



Vol. XXIL] OCTOBEE, 1889. [No. 317. 



INVESTIGATION OF VARIATION. 

 By the Editor. 



During the past few years great strides have been made 

 towards a better knowledge of the range of variation in insects. 

 A decade ago the number of students of this interesting subject 

 could be counted by units ; their ranks now include many, in all 

 parts of the world. It is highly satisfactory to find that latterly 

 there has arisen such an appreciation ; and much has recently been 

 done towards a discovery of the causes of variation of colour and 

 shape of animals, beyond the generally accepted one of " adaptation 

 to the environment." This is, of course, satisfactory so far as it 

 goes ; but as yet the whole knowledge on the subject is very 

 small, in comparison with that which has still to be attained. 



Every credit is due to those who have done much towards 

 unravelling the tangle, but that much is little ; and, after all, it 

 is only individual eifort. Individual action, although of the first 

 necessity, rarely brings forth results commensurate with the 

 individual labour bestowed upon a little known subject. The total 

 material available to one person, unless in very exceptional cases, 

 is rarely sufficiently exhaustive to enable exact facts to be attained. 

 Again, the publication of such facts must be intermittent and in 

 various channels, which may after lapse of time become over- 

 looked, so causing unnecessary labour in going over already 

 trodden paths. To publish such facts in large form is expensive, 

 when properly illustrated, and generally a tax upon the author, 

 the demand for his book being confined to the limited number 

 who take an active interest in his work. Thus his chances of 

 disseminating his hard-won knowledge are fettered. Further, his 

 facts published, after all his trouble and expense, may not be the 

 best facts which he possesses, or best arranged for the advance- 

 ment of knowledge. Some one else may have other facts, which, 

 if incorporated, would greatly enhance the value of the work, 



ENTOM. — OCTOBER, 1889, Z 



