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varieties, and wlien one neglects the latter, one neglects also the most strikiiig facts 

 which can serve to explain the origin of species. The highest degree of variation 

 of a Papilio is the development into another species. The highly interesting 

 r. ixnitdiT Godm. & Salv. from the Solomon Islands stood rather isolated nntil now; 

 in this paper two varieties of 1'. .virprdon L. are cliaracterised which at once 

 explain the pecnliarities in the character of P. isaiidcr, and show that it differs from 

 snrpcrlon oul}' quantitatively. The Bismarck Archipelago is inhabited by a repre- 

 sentative species of P. cfldrua Cram, with iuterrnpted median band to the forewings, 

 P si'qoiifKf Godm. & Salv. ; from the extent of variation of seffonu.c and the 

 Solomon Islands' codri(s, we can conclude that segomix was derived from rodnis. 

 The distinguishing characters of P. segonax, i.sander, and many other species 

 (P. ncheron Grose Smith, epaminondas Oberth., oi-natus Kothsch., pi'i/f/rs Wall., 

 lorqiii)iianus Feld., etc.) are more or less indicated in certain varieties of their 

 nearest allies ; there is uotliing entirely new in their structure, pattern, or shape, and 

 they are, indeed, in a ]>hyllogenetical sense, only further developments of P. codrus, 

 snrppdon, forhesi, antipliates, peranthus, respectively. But the chain of intergrada- 

 tions between P. codrus and segonax, sarpedon and isonder, (intiphntcs and 

 epaminondas, peranthus and pericles, etc., is incomplete, and tljere are exact parting 

 lines between these Papilios. It is therefore possible to give the limits of variation 

 of a species such as we observe them in the individuals brought home from the area 

 inhabited by the species, and to come to a scientific decision about the distinctness 

 or non-distinctness of a Papilio form. If the characters of a Papilio are only 

 quantitatively ilift'erent from those of another, it is a priori probable that both forms 

 belong to one species : but if a long series of either Papilio from different places, and 

 collected at dift'erent times, does not furnish us with a continuous bridge from one 

 Papilio to the other, we have no right to fill up mentally the space between the two 

 forms by intergradations which do not exist according to the state of our know- 

 ledge. We consider, therefore, all those Pa])ilios as varietal forms of tlie same 

 species which are connected with one another, in one or both sexes, by intergrada- 

 tions ; and treat those forms as specifically <listinct, however closely allied they may 

 be, which no chain of intergraduate specimens combines. 



The reasons which induce the scientist to give names to the species, genera, 

 families, etc., ajiply also to the variations, and the varietal forms have accordingly 

 been treated in this revision under names of their own. The authors of treatises 

 about general zoology, or generic classification, can be contenteil with the names of 

 the species, and the entomologists who begin to study the Papilios, or are not able 

 to perceive minute ditferences, or collect only for the sake of collecting, will also 

 much facilitate matters for themselves by abandoning the varietal names 

 altogether. 



In accordance with the usage of designating a species witli a generic and 

 specific term, and of writing Papilio eurypylus L. instead of " genus " Papilio 

 ' species " eirrgpyltts L., we employ for the subspecies three terms, the generic, 

 specific, and subspecific term, and write thus : Papilio fiurypi/ltis axion Feld. 

 Phyllogenetically interpreted P. eurypylus axion Feld. means that the Indian axion 

 Feld. is a local form of the Amboinese eurypylus L., i.e. that axion has developed 

 from curypjylus, which is most probably erroneous. The Amboinese eurypylus is 

 nothing else but also a local race of a Papilio which ranges from India to the 

 Papuan Islands and to which the first name {eurypylus) given to one of its sub- 

 species is applied. 



