( 496 ) 



may pass over a qnantitatively iusignifieaut affection of an eye as being trifling ; 

 while a good oplitlialraist will at a glance prononnce this trifling affection to be 

 the beginning of a very serions disease of the eye. In short, it does not require 

 any special power of thought to perceive that the answer to the cjnestion " whether 

 a difference is conspicnons enough " depends on each individual author. The 

 answer is dependent on the person — i.e., it is arbitrary ; and arbitrariness in 

 scientific research is a vice not to be suffered. It is a degradation of systematic 

 work against which we earnestly protest. 



We can demonstrate a difference, and can show that it exists in all individuals 

 from the respective district which are known to science. If we do so, we record 

 only a fact in nature. Be the distinction easy or difficult to perceive, it is there. 

 We are not the authors of the distinction. We have only demonstrated its 

 existence, and we cannot accept any re])roach for its demonstration, its occurrence, 

 or its smallness : the demonstration being our duty as scientists and the character 

 having come into existence without our influence. The answer to the question 

 "whether there is a difference" is always possible to be proved to be in the 

 positive or in the negative. There is nothing arbitrary here. 



Since the conspicuist can only arbitrarily decide which forms he will recognise 

 and which not, it is obvious that one conspicuist will treat as synonymous what 

 another will consider worthy of recognition, and that an author who trusts too 

 implicitly the correctness of the synonymy as given by such consi)icnists will re- 

 describe as new the very same form which his guides have put down as synonymous. 

 More frequent and of greater consequence is another danger to which the work 

 of conspicuists is exposed. Being accustomed to putting together as identical 

 what is not very distinct-looking, and to treating conspicuously different forms 

 as specifically distinct, he will naturally constantly be deceived by similarities 

 in species and dissimilarities in varieties. He will not be able to come by himself 

 to a correct result in the case of distinct species which are diflScult to distinguish 

 in the ordinary way, and he will not find out for himself from the specimens 

 which Conspicuously different forms are specifically distinct, which are geographical 

 races, and which are seasonal (or individual) varieties. Dr. Pagenstecher 

 maintains that the interesting varieties produced by soil and season can be fixed 

 without giving names to them. We maintain that they cannot, and that the 

 " simplification " advocated by Dr. Pagenstecher tends to prevent an author 

 from even perceiving the geographical differences and from distinguishing between 

 conspicuous specific characters and non-specific characters in many cases. 



Let us illustrate what we have here said by looking at the result of the 

 " simplified " treatment of the Lepidoptera of Baron von Erlanger's expedition 

 enumerated in the list quoted above.* There are three species of Amauris 

 mentioned in that list : — 



1. Amawris niatius. — "The form dominica/ms, differing from the West African 

 form niaeius in the greater expanse of the white area of the hindwings, is severally 

 represented; from Gerwidscha, 14. xii. il(J. and especially from Mombasa 

 29. vii. 01." 



We have not seen a Gerwidscha specimen, but knowing this place to be in 

 the North-East African subregion we are practically certain that the Gerwidscha 



• We are very sorry that we have to mention Dr. Pagenstecher's name so often ; but we do not 

 see how we can present the case clearly to the reader without doing so, and without talking illustrations 

 from Dr. Pagenstecher's paper in which we are personally blamed for our standpoint. 



