282 THE JOURNAL OF BOTANY 



volume. It is of a still larger size than the previous volumes, and 

 the enormous number of papers referred to, and of plants 

 mentioned in these papers, is the best vindication of the useful- 

 ness of such a work and demonstration of its value. When we 

 look through the pages of these volumes, we cannot fail to be 

 struck with the immense amount of literature dealing with fossil 

 plants which is published annually and scattered in such diverse 

 periodicals that some of it may elude the vigilance even of the 

 specialist. While the most industrious botanist finds it difficult 

 to keep in touch with all the literature of his special subjects, the 

 painstaking work of Dr. Jongmans makes it possible for anyone 

 to ascertain easily the year's work on palaeobotanical subjects, or 

 on any fossil plant or group of plants. This should be especially 

 useful for those whose work does not bring them very extensively 

 into contact with palasobotanical memoirs, but who are studying 

 plants allied to some of the fossil forms. For example, opening 

 the volume before us at random, we find no less than eighty-one 

 references to species of Myrica, belonging to periods between 

 Cretaceous times and the present day ; many of these might 

 escape the notice of a worker on this genus. 



In England, we too often fall into the error of associating 

 Paleobotany only with the study of Carboniferous plants, and of 

 forgetting that it includes the study of all ancient plants whose 

 remains are found buried in the earth. But though the papers on 

 Carboniferous plants mentioned in the present volume are the most 

 numerous, yet they do not form much more than a quarter of the 

 total number of the papers recorded. In this connection it is 

 interesting to notice the numbers of papers dealing with the 

 plants of the different periods. In this volume the number of 

 papers quoted as dealing with Devonian plants is 14, Carbo- 

 niferous plants are dealt with in 152, Triassic in 29, Jurassic in 

 42, Cretaceous in 80, Tertiary in 100, and Quaternary in 135, the 

 figures being approximate in each case. While a large percentage 

 of the papers on Palaeozoic plants come from the hands of English 

 botanists, only seven out of the one hundred and thirty-five papers 

 which deal with Quaternary plants originated in this country. It 

 is much to be regretted that English botanists take so little 

 interest in the plant-remains in comparatively recent deposits, 

 such as peat and the ancient forest beds of pre- and post-glacial 

 age, for this study almost certainly provides the key to many 

 problems of the distribution of our plants. For example, the 

 presence of the Lusitanian flora in the West of Ireland may well 

 be due to the warmer winters of a milder post-glacial period, of 

 which there is some evidence. This study not only throws inte- 

 resting light on the distribution of many elements in our flora, but 

 also on the past histories of many individual plants. Some idea 

 of the activity of Continental workers in this field may be ob- 

 tained by the perusal of a volume which has provided many refer- 

 ences in Jongman's list, viz., the work published by the Stockholm 

 International Geological Congress entitled Die Veranderungen des 

 Klimas seit dem Maximum der letzten Eiszeit. 



