226 The hish Naturalist. September, 



is evidence for the survival through the Ice-age of any of our present 

 fauna to the south or west of the present Irish area. He gives as an 

 original suggestion towards the solution of the problem, a post-glacial 

 land-connection between Ireland and Brittany, imagining a southward 

 extension of the presumed elevation along the western Irish seaboard, 

 accompanied by a subsidence towards the east, which cut off direct com- 

 munication between Great Britain and Ireland. Mr. Kane is inclined to 

 lay much stress on climatic and environmental influences and com- 

 paratively little on geographical changes. This is a disputable point 

 upon which, as upon the pre- or post-glacial question, much difference of 

 opinion can only be expected. We have no doubt that the pre- 

 Pleistocene age of at least a considerable section of our fauna will some day 

 be acknowledged on all hands. And it is becoming evident that extreme 

 scepticism about the glacial conditions, as interpreted by most geologists, 

 need not necessarily accompany belief in the survival of many of our 

 animals and plants through the Ice-age. Not only, as has been so often 

 pointed out, may a temperate or even a semi-tropical flora prevail in the 

 neighbourhood of great glaciers, but the surface of a glacier may itself, 

 as evidenced by the present conditions in Alaska, bear soil and vegeta- 

 tion which may afford shelter to animals. The fascinating problems of 

 Irish natural history will not be fully solved until an exhaustive study of 

 the Pliocene and Pleistocene deposits has been correlated with the fullest 

 pc ssible accumulation of distributional facts. The two insect-lists here 

 reviewed bring us an appreciable step nearer to the second of these most 



desirable conditions. 



G. H. G. 



BRITISH AND IRISH LIVERWORTS. 



The HepatlcsB of the British Isles, being figures and descrip- 

 tions of all known British species. By W1LI.IAM Hknry Pearson. 

 Vol. I., Text, vi. 4- 520 pp. ; Vol. II., 228 Plates. London: Lovell, 

 Reeve, & Co., 1902. Super Royal 8vo. Price, with coloured plates, 

 ;^io 10s. ; uncoloured, £']. 



The study of the British Hepaticae has been retarded for many years 

 for want of a good work on the subject. Hooker's ** British Junger- 

 manni^," a splendid work, published in 1816 in folio, soon went out of 

 print. Dr. Carrington's book, commenced in 1874, came to an end 

 before a quarter of the species had been described. Mr. Pearson has 

 now supplied this want, and, in some respects, in a way which has not 

 been done before for the British species. A very full and detailed 

 description is supplied of each species, with measurements of all 

 the parts, and a whole plate is devoted to the delineation of each. 

 The work is preceded by a short practical Introduction, which 

 contains comparative tables of the sizes of the plants and of their leaf- 

 cells, and a diagram and table of the direction of the leaves, which will 

 be most useful. This is followed by a glossary of terms, not useless 

 either, since it contains the word umbraculifonn, and by a Bibliography. 



