RHOPALOCERA NIHONICA 



9 



found southward from Japan to Australia, and westward as far as Africa, but the Main Island of Japan is 

 probably its most northern limit. It is not known in Amurlan d. 



Many years ago, I observed a hybernated female, of the form ma nda rina , depositing its eggs on 

 Lespedeza juncea. From these eggs I was greatly astonished by breeding several of the form hecabe y wliicli 

 had been described by Linnaeus, and well k now n for over 100 years. 丁 his was so unexpected and contrary 

 to all the then accepted ideas concerning the im m utalulity of species, that I suspected some eggs or larva 

 of hecabe had strayed into my breeding cages, and hesitated to publish my discovery without further 

 corroboration. In following years I again and again tried the same experiment, with the same results, and 

 then sent an account to the London Entomological periodicals, where the statement was, and still is, 

 received witn incredulity ； but, as I am sure, it is a positive fact, and it will be easy for any one who may doubt 

 it to undertake the task or investigation. I know that several eminent describers have spent a lifetime in 

 separating the forms of this species, and they naturally feel annoyance that I should have so outrageously 

 upset their pet theories and proved that they have been engaged in a useless letting down of " bottomless 

 buckets into empty wells and drawing nothing up." A fine illustration of this sort of work is Mr. Butler's 

 paper on the Japanese Terias, published in Trans. Ent. Soc. London, 1880， Part 4， the only realjy useful 

 part of which is the coloured plate accompanying the paper ； it gives a series of forms, all multiformis. 



By placing* half of a brood of larva in a cool place and hair m a warm one, I have simultaneously 

 produced a mixture of the two forms, some perfect hecabe (hot), and some wicnidcwina (cold), at a time 

 of year when naturally only hecabe is found. With reference to Mr. Butler's remarks concerning 

 hybrids, Trans. Ent. Soc. London, 1880, Pt. 4， genuine hybrids do actually occur between hecabe and 

 jnandarina naturally. Mandavina appears on the cold mountains much earlier than on the plains, and 

 these fly down and mix with hecabe, producing one or more broods late in the autumn, of numberless 

 intermediate varieties, showing all transitions between the two parent forms. 



This insect is a most excellent illustration of the transmutation of species. If it could be transported 

 to a cold, even climate like England, only the inandarina form would be found, and its connec- 

 tion with hecabe would not even be suspected, as they differ in every respect as much as any two 

 species of the family ； with an increase in temperature in Japan, viandarina would disappear, and only the 

 hecabe form would be found, as at Singapore and other tropical places where I have collected. The hecabe 

 form is one of the butterflies the males of which are supposed to be more numerous than the females, but 

 this is not a fact, as I find, when breeding them, that both sexes are about evenly represented. The males 

 are fond of settling in numbers on dam p spots in pathways, or flying about in the open, and are easily- 

 captured in large numbers. The females have to be sought after among the herbage and undergrowth, 

 and are much less easily found, and this is the reason of the apparent disproportion of the sexes ； the result 

 of the difference in habits of the sexes is seen in the different colour of the males and females, the males 

 are always a bright yellow and the females much lighter, the latter being much less exposed to the action of 

 light. These remarks apply only to the hecabe form, and not to mandarina. The latter appears during 



