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fauna, and therefore, instead of being a contribution to our knowledge of tbe 

 insects and their distribution, hamper tbe student in understanding the facts of 

 distribution, variation and evobition, wbicli stand all in ver\' close connection. 



"We have shown iu various places that geographical variation is very different 

 from non-geographical (seasonal, individual) variation. The geographical variation 

 is the beginning of tbe ramification of one species into more. From it has 

 resulted the enormous variety of existing species, each breeding true. The result 

 of individual and seasonal variation is di- or polymorphism within a species, 

 each form reproducing itself and the others, or the result may be modiKcation 

 of one species into one other. Geographical varieties differ in various degrees. 

 They represent various steps in the evolution of daughter-species. Whoever 

 studies the distinctions of geographical varieties closely and extensively will smile 

 at the conception of the origin of species per saltum. For he will find that in 

 the large majority of cases the geographical distinctions are minute, and he will 

 see further that there is a complete gradation from geographically separate varieties 

 of a species which are very distinct from one another in colour, pattern and 

 structure in all individuals, to geographically separate portions of a species which 

 do not exhibit any distinctions. It is just this prevalence of minuteness in the 

 geographical distinguishing characters which gives us the best insight into the 

 working of evolution. Hence it is of the highest importance to demonstrate 

 wherever one can the prevalence of minute distinctions in geographically separate 

 portions of a species — a demonstration which depends entirely on the intensity 

 and minuteness of the research of the specialist in the systematics of the respective 

 group of animals. 



The quantitatively small difference between geographical varieties does not 

 suffer in interest from its smallness. For the minuteness of the distinction 

 demonstrates directly that the variety is not the result of selection (by enemies) 

 in the ordinary sense. The differences between the Abyssiuian variety of Argi/nnis 

 hi/perbius and the North Indian variety become perceptible only on close com- 

 parison, and cannot possibly be of direct selection-value. The more such 

 geogiaphical races (= subspecies) characterised by minute distinctions are pointed 

 out, the more direct selection is eliminated from the initiatory factors of evolution. 

 As variation is the basis of evolution, the intimate knowledge of the products of 

 variation within the species is the only safe substructure for theories on evolution. 



Therefore we claim the detailed study of the variation of the species to be 

 one of the main objects of the modern systematist, who will look upon the varieties 

 always as indicating change, the change in characters taking (or having taken) 

 place either in connection with a change of the environnvjnt or without it. Having 

 this in mind, the student of insects will a priori be an unbeliever in the occurrence 

 of species over wide areas without the species being split up in the physio- 

 graphically different and separated districts into geographical varieties, and he will 

 require a special exjilanation if a wide distribution without corresponding change 

 in characters is observed. When we saw that the Oriental Argi/iniis hi/perbius 

 was recorded from Abyssinia, we were convinced, without having seen specimens 

 from that country, that the Abyssinian individuals differed from Oriental ones. 

 AVhy? Because we knew Abyssinia to be a fauuistic district inhabited by many 

 specialities, and because we knew Aryipmis h/jperbius having develojied in the 

 Oriental Region into a number of easily recognised subspecies (= geograpliical 

 varieties). It would be anomalous if the Abyssiuian individuals were not different. 



