ft'om Nikko^ Central Jajpan. 137 



It appears to me that there must be sufficient variation of 

 conditions in 260,000 square miles of insulated land, divided 

 into three larger islands by intervening straits, and exhibiting 

 considerable degrees of elevation, to render the existence of 

 different species in the same group less a probability than a 

 certainty. 



That it does " require special training to appreciate " spe- 

 cific differences is a truism which no entomologist who has 

 specially studied any branch of his science will be inclined to 

 dispute ; for that very reason it is unwise for any natura- 

 list, when taking up the study of a branch of science com- 

 paratively new to him, to plunge at once into the most difficult 

 genus in that branch, and criticise the work of all previous 

 labourers in the same field. 



Whilst referring to the paper by Mr. Elwes, it will save 

 further trouble to call attention now to some observations of 

 his on p. 141. Mr. Elwes says that I have " described no 

 less than four supposed species and varieties nearly allied to 

 this," meaning G. erate ; and, as though to confirm this sur- 

 prising statement, he inserts in brackets " see P. Z. S. 1880." 

 Although not aware that I had described any species allied to 

 G. erate from Candahar, either supposed species or variety, 

 I took the trouble to look through the ' Proceedings of the 

 Zoological Society of London ' for 1880 ; but I could not find 

 any descriptions of Golias by myself. It is a pity that Mr. 

 Elwes did not give a reference to the page, as it might have 

 tended to explain his meaning. Mr. Elwes then proceeds to 

 say that he entirely fails to follow my distinctions, and goes 

 on to prove it by declaring that what I call G. erate is like the 

 specimens of that species from South Russia and the Punjaub, 

 that what I call G. helictha differs from C. hy ale just as Le- 

 derer says it does *, that what I call G. sareptensis is identical 

 with the form of Hyale found all over Asia, from the Hima- 

 layas to Japan (specifying, however, three forms which have 

 hitherto come only from Japan), and, lastly, that what I call 

 G. pallida is just what Staudinger says it is, a white variety 

 of G. erate ? . 



I need say no more respecting this paper on Golias ; it 

 possibly may not seriously affect the study of the genus, since 

 most Lepidopterists will probably hold the same opinions now 

 as before its publication ; the only cause for regret is that 

 Mr. Elwes did not pause before publishing that in haste of 

 which it is possible he may, after more profound study, repent 

 at leisure. 



* Mr. Ehves repeats the obviously erroneous suggestion that C. helictha 

 is a hybrid between two species not occurring in the same country. 



