( 17« ) 



gradual decrease, ending in total obliteration, of the hairy stripe on the forewing of 

 the male, and a slight and gradual increase of the breadth of the green band, we can be 

 (piite certain that P. montaiius Felder, without hairy strijie and with rather broader 

 band, is only an extreme variation of 1'. cri/w P'abr. Tlie number of species based on 

 individual characters is very great. 



The limits of variation of a species do not often exactly correspond at ditferent 

 jilaces of a certain district. Every field-entomologist knows that, within a district 

 where the usual or typical form flies, there are often some special localities where 

 the specimens of that insect vary to a greater extent, and that at such a locality 

 some or all the individuals of a species stand outside the usual limits of variation of 

 that species. These varieties, however, are iigaiu connected with the usual form of 

 the insect by intergradations, and thus jirove to be indeed varieties. As we further 

 know from the experiments of Dorft'mcister, Weismaun, iStandfuss, i\Ierrifield, and 

 others, that nnder altered circumstances the limits of variation can be much dilated, 

 it is a jiriori probable that the specimens of a Papilio living on a peculiar ]ilace, like 

 swamps or valleys, are influenced in a ditferent degree or even in a different direction 

 than those living on desert land or at higher elevations. Here we have localised 

 varieties; but the material contained in collections very seldom tells us anything 

 about the localisation of varieties within a limited district, as the specimens are 

 mostly simply labelled '• Sikkim," " Assam," " Borneo," etc. Indeed, only a local 

 observer who collects for many years at the same place can go in for a special study 

 of the distribution of the varieties in his district. The local lists we have of Eastern 

 Papilios give already here and there observations in this direction, but the notes are 

 so scanty that in this paper that kind of localised variation could not be dis- 

 tinguished from the general imiiridual variation of the specimens of a given 

 district. 



Besides the effects of localised conditions of life we observe a change of the 

 characters in the Papilios caused by the different climatical conditions of the seasons. 

 While, however, it is well known that the generations of Papilios subsequently 

 following one another in the course of the year in the temperate regions differ 

 remarkably {P. xanthus L. and xtithulus Brem. ; P. bianor maacki Men. and niddei 

 Brem. ; P. polyctov Boisd. and joeez-o^ra Moore; P. iiudalirius feistkameli Dup. and 

 lutteri Aust.; etc.), we have scarcely any notes about the differences of the 

 generations of the dry and wet seasons of the tropical regions. We know in a few 

 cases that a certain variety occurs only during some months of the year, and can 

 sometimes conclude from the dates of ca])ture of the specimens in collections that 

 a Papilio varii's witiiin the same limits during certain months of the year; but 

 detailed observations are almost wanting. The spring and summer generations of 

 tlie Cashmerian P. polyctor Boisd. are different, while the Sikkimese representative 

 form of P. polyctov, namely P. polyctor ganesa Doubl., is seasonall}' monomorphic ; 

 the Jajiariese P. unrpedon L. is seasonally dimorphic, while the Indian surpedou is 

 moudniorphic ; the Chino-Japanese P. hinnot Cram., /-■. xanthua L., P. machaon L., 

 and tiie Va\a,Qa.xct\c P. podalirius'L.,wc& conspicuously seasonally dimorphic, while no 

 Indo-Australiau species of Papilios shows, to our knowledge, so marked differences 

 between the succeeding broods. The influence of the low temjierature of the winter 

 in temperate regions seems, therefore, to be much greater than tlie influence of tlie 

 dry season in Indo-Australia. We distinguish accordingly the ■•scnsomil IVoni the 

 indiridual variation only in the case of some Chin(i-.lai)anese, X.W. Imlinn. and 

 Palaearctic species. 



