348 THE ENTOMOLOGIST. 



tion both geographically and vertically, if we thus can correctly 

 interpret the fact that the most closely allied representatives of 

 this arctic and alpine group are elsev^here (in the southern 

 hemisphere) to be found in the alps of New Zealand {Argyro- 

 phenga), and in the Chilian Andes {Argyrop) ; while the well- 

 known genus Erehia was once in an almost similar position, 

 judging from the fact that it possesses very near representatives 

 in the Southern Andes of South America, as well as in the high- 

 lands of South Africa, several genera of which were indeed for- 

 merly included in that of Erehia. If, however, in the latter case 

 the genus may not have been so completely cosmopolite, I do 

 not see that the contention cannot hold good with regard to the 

 former; for if, as Darwin suggested, the alpine fauna of the 

 American Andes was derived from the regions to the north 

 during the glacial epoch by means of the elevated mountain 

 chain crossing the equator, I fail to perceive how it can account 

 for the occurrence in a similar manner, in the isolated archi- 

 pelago of New Zealand, of the genus Argyrophenga, which is so 

 closely allied to (Enis of our northern hemisphere. In this con- 

 nection, I may here remark that the marsupial mammals which 

 are now so abundant and characteristic of the Antipodes were, 

 during Miocene times, almost equally as plentiful in Europe, in- 

 cluding the British Isles. 



Another important item in support of the hypothesis that 

 the organic conditions exert a paramount influence upon their 

 distribution is to be found in the fact that many species of 

 plants and animals occur in certain zones upon some mountains 

 which do not correspond with their occurrence in other zones 

 further north. A typical instance of this is to be found in the 

 Austral species Lampides hcetica, which in the region of the Alps 

 only inhabits the lower valleys of the mountains, but which, 

 both in the Pyrenees and the Himalayas, occurs at greater 

 elevations both comparatively and relatively, having been found 

 in the former range at the altitude of 8000 ft. under circum- 

 stances which conclusively prove that it could not have been a 

 mere immigrant there. Conversely, a few instances could be 

 given to show that certain species do not occur at such corre- 

 sponding high zones as is the case further north. In certain 

 instances also, species are known to be confined to intermediate 

 zones in comparison to those they occupy in other mountain 

 chains, or even in different parts of the same range. The 

 general rule is, however, the other way, and their vertical dis- 

 tribution corresponds with remarkable uniformity in relation to 

 both the accompanying phyto-geographical and the climato- 

 logical conditions of regions and mountain ranges widely sepa- 

 rated. 



This remarkable regularity, however, does not at all detract 

 from the hypothesis that it is the organic environment which 



