298 NATURAL SCIENCE. May. 



crystallised in the schists after the schistose structure was developed^ 

 the author sounds a note of warning as to good idiomorphism being 

 an infallible sign of the early genesis of crystals in igneous rocks. 



Alpine Flora. 

 The study of present conditions in the Arctic Regions is so neces- 

 sary if one wishes to understand the bygone history of our flora and 

 fauna, that we are glad to see that Mr. H. D. Geldart takes this view 

 in his presidential address to the Norfolk Naturalists' Society. Com- 

 paring the existing flora of Greenland with the flora of Britain during 

 the Glacial Epoch, he is no doubt right as to the power of part of the 

 arctic and alpine flora to survive, however cold it may be. We may 

 point out, however, that it can only survive if there still exist tracts of 

 land bare of snow and ice during the summer. The British alpine species 

 may have lived throughout the Glacial Epoch in the South of England 

 or on the ice-free summits of our north country ; they cannot well have 

 lingered in the flatter districts of East Anglia, where the ice-sheet 

 seems to have been continuous. Mr. Geldart thinks that the Green- 

 land flora likewise inhabited Greenland through the Glacial Epoch ; 

 but he does not allow for the former greater thickness and extent of 

 the ice, which then, in all probability, entirely hid the small areas 

 now free from snow during the summer. The marks of glaciation in 

 Greenland usually extend far beyond and above the present limits of 

 the ice. 



The Antarctic Continent. 



In our issue of last month we dealt with recent views upon the 

 former greater extension of the Antarctic Continent. A correspondent 

 has pointed out to us the important evidence in favour of this view 

 that is furnished by a study of the earthworms of the Southern 

 Hemisphere. These animals are, generally speaking, entirely wedded 

 to the soil ; they are impatient of sea-water, and possess but few 

 facilities for assisted migration ; hence they are valuable as a help 

 towards determining the probabilities of earHer land-connections. 

 It is a striking fact that there is the closest similarity between the 

 earthworms of Patagonia, New Zealand, and such of the intervening 

 islands as have been explored. It appears from the papers contain- 

 ing descriptions of the earthworms of the " antarctic area " by 

 Michaelsen, Rosa, and Beddard, that the bulk of the indigenous 

 Oligochaetous inhabitants of these regions of the world are members 

 of the genera Acanthodrilus and Microscolex. Indeed, in Patagonia 

 and the Falkland Islands no other species at all have been met with. 

 In New Zealand, there are only two earthworms which are not of 

 either of those two genera or which do not belong to the three genera 

 Octochcetus, Deinodvilus, and Plagiochceta, closely allied to Acanthodribis. 

 South Georgia, Kerguelen, Marion Island, and MacQuarie Island 

 also possess two or three species of the genus Acanthodnhis. Only 



