( 180 ) 



but as the first sometimes acquires the white murkinsrs on the liindwings, and tlie 

 latter has them occasionally indistinctly dcvelojieil, there is no character by which 

 the two Pai)ilios are always separated. Such localised forms can, therefore, uot be 

 regarded as speciiically distinct, bnt represent, together with other forms, the degrees 

 of variation of iin insect. 



To sum np, we practically distingnish fivo jirincipal degrees of variation of 

 a species : — 



1. A species witii a wider range develops mostly in the diiferent districts into 

 more or less well-characterised local or geographical forms (races), which are termed 

 in this j)aper xufj.yx'ciffi. PVlder's P. tcredon (Ceylon and S. India), milon (Celebes, 

 Sanghir, and Talaut, Sulla Islands), anthedon (Moluccas), chori'don (Queensland), etc., 

 are all subspecies of P. sarpedon L. (India, Sumatra, Java, Borneo, Philippines, 

 Japan) ; .and all the subspecies, together with the Linnean i^nvppdnn, compose the 

 entire species. 



2. If only a relatively small number of sjiecimens in a certain locality, uot all 

 over the area inhabited by the subspecies or species, exhibit a peculiar character, 

 while the greater mmiber are not different from the usual type, we have a localised 

 indiridual variation, which we term loml individmil aberration, aberratio alicuiiis 

 loci = (lb. loc. T. priamua vrrillianus ab. loc. bornemanm Pagenstech. does not 

 occur on the Solomon Islands, being restricted to the Bismarck Archipelago. 



3. The various generations of a species or subspecies are sometimes difl'erent 

 from one another ; the species is divided into seasonal forms, which are termed here 

 aberratio genei-ationis aestimlis seu rcrnaUs = ab. gen. aet^f. sen vern. : P. .mtitliii.^ 

 ab. gen. vern. xutkulus Brem. ; P. polydor ab. gen. vern. peeroza Moore. 



4. Among the individuals of a species or subspecies some are occasionally so 

 aberrant that the term individual aberration or simply aberration is proposed for 

 them : P. machaon ab. niger Heyne. When the aberratiou is confined to one se.x, 

 the designation (J,?) of that sex has been added : /'. hianor iti/fanius c?-ab. dialis 

 Leech : 7'. priann/s po.^eidon ?-ab. arcliideus (Gray). 



o. There are a number of Papilios {P. adiates Sulzer, romuhis Cram., etc.) 

 which stand isolated, uot being connected with other forms by a continuous chain of 

 intergradations. Though rearing alone can definitely decide whether these Papilios 

 are all varieties of others, it is mostly beyond doubt tliat we have here to deal with 

 forms of polymorphic species. For these forms, which all belong to t\ie. female sex, 

 of certain polymorphic species {P. pohjtes L., P memnon L., P. rumanzovius 

 Eschsch.), the term feminue forma (?-f.) is proposed : P. memnon ?-f achntiade,^ 

 Esper. When the ?-f is restricted to a certain district, we term it ?-f. loc. = ? -f 

 alicuius loci. A strict parting line between " ?-al).'" ami '■ 9-f." cannot be 

 drawn. 



With this detailed terminology the various kinds of variation, the dill'erent 

 steps in the development of the ehara(^ters of a species, can be kept sejjarate. Since 

 the word variety (carietas, Yarietitt) has been, and is, applied in science in- 

 discriminately to every kind of variation, it has been avoided in this pai)er as 

 a special term. 



The systematist who niidertakes to characterise the families and genera without 

 an extended knowledge of the species, which are the foundation-stones of the 

 zoological system, will often come to erroneous conclusions, and so will everybody 

 who characterises species without studying the variations. It is impossible to 

 understand the relationship of closely allied sjiecies witiiout a knowledge of tlic 



