1878.] HEMIPTERA OF ST. HELENA. 459 



Here I may be permitted to quote a remark by Mr. Darwin 

 on this point l : — " In Africa, several forms characteristic of Europe 

 and some few representatives of the flora of the Cape of Good Hope 

 occur on the mountains of Abyssinia. At the Cape of Good 

 Hope a very few European species, believed not to have been 

 introduced by man, and on the mountains several representative 

 European forms are found which have not been discovered in the 

 intertropical parts of Africa. Dr. Hooker has also lately sbown 

 that several of the plants living on the upper parts of the lofty 

 island of Fernando Po and on the neighbouring Cameroon Mountains, 

 in the Gulf of Guinea, are closely related to those on the mountains of 

 Abyssinia, and likewise to those of Temperate Europe. It now also 

 appears, as I hear from Dr. Hooker, that some of these same 

 temperate plants have been discovered by the Rev. R. T. Lowe on 

 the mountains of the Cape- Verde Islands. This extension of the 

 same temperate forms, almost under the equator, across the whole 

 continent of Africa and to the mountains of the Cape-Verde 

 archipelago, is one of the most astonishing facts ever recorded in the 

 distribution of plants " 2 . Mr. Darwin then proceeds to show how 

 iu a glacial epoch the temperate flora might have invaded the whole 

 of Africa, and at the return of warmer conditions been driven up the 

 mountains, or in some cases become gradually acclimatized. 



In connexion with this possible, and, as it seems to me, probable, 

 community of origin of the floras of the Cape (in part) and of St. 

 Helena, the significance of the occurrence at the former place of 

 several Coleoptera and Hemiptera closely allied to, if not identical 

 with, St.-Helenian species, is not to be overlooked 3 . 



It is not to be wondered at, then, that we do not find, in the parts 

 of Africa nearest St. Helena, much, if any, relationship to the island 

 fauna and flora. That such relationship, so far as community of 

 origin is concerned, once existed, I have little doubt ; but the return 

 to tropical conditions and the reestablishment of the tropical fauna 

 and flora have obliterated, except on the mountain-summits, all 

 traces. Aud St. Helena by its isolated position and temperate 

 climate (the mean temperature of the year being only about 61°) is 

 to all purposes a mountain. 



The affinity of the Hemipterous genus Megarhaphis to the 

 African Macrorhaphis (of which one species is from the Cape, and 

 the other. — rather doubtful as to the genus — is from the Congo) 

 seems to be an exception ; but as we do not know the exact nature of 

 the locality whence the Congo species was derived, and as it is as 

 likely as not to be a mountain and not a tropical insect, it may after all 

 prove our case by being a descendant of one and the same Palsearctic 

 ancestor as the Cape and St.-Helenian species. 



There still remain some elements in the fauna and flora of St. 

 Helena to be accounted for. 



1 Origin of Species, p. 337. 



2 See also Professor Oliver's ' Flora of Tropical Africa,' in which the 

 occurrence of several species, not only European but even Arctic, is recorded. 



3 Certain European Hemiptera are also natives of the Cape. 



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