228 



KNOWLEDGE. 



June, 1913. 



BOTANY. 



The Moorlands of North-Eastern Yorkshire. — By F. 

 Elgee. 356 pages. 3 maps. 71 figures. 8j-in. X 5i-in. 



(A. Brown & Sons. Price 15/- net.) 



As the author rightly claims in his preface to this work, 

 representing the results of his long-continued observations 

 on the geology and natural history of the eastern moorlands of 

 Yorkshire, we have here for the first time a comprehensive 

 book dealing with a British moorland area from a scientific 

 standpoint. The ecology of moors in various parts of Britain 

 has been dealt with in memoirs by members of the British 

 Vegetation Committee, while among Continental memoirs two 

 stand out prominently — Graebner's Heide Nord-Deutsch- 

 lands and Friih and Schrbter's Moore der Schweiz — but 

 the present work differs from all these in that it deals not only 

 with the plant life of the moorland but also the geology and 

 zoology in their relationship and interdependence. 



The author does not claim to have produced a definite 

 monograph, and though every aspect of the moorlands has 

 been touched upon in his work, an exhaustive treatment of 

 each topic has not been attempted ; for instance, detailed 

 descriptions of moorland plants and animals have been 

 omitted, as these are found in works dealing with the British 

 flora and fauna. By judicious selection, and owing to his 

 having taken into account the current literature of the topics 

 dealt with, he has produced a striking contribution to ecology, 

 and since he indicates throughout the work the various 

 problems in moorland ecology which are still open to solution, 

 and upon which further search is required, the book is one 

 that should stimulate other workers in various districts to take 

 up some of the many questions raised. For instance, he 

 points out that the investigation of the peat deposits, layer by 

 layer, is a piece of research that is urgently needed, because 

 of the light it would throw upon climatic changes in post- 

 Glacial times and upon the development of the " mosses " 

 (moss-moors, Hochinoore). 



The greater part of the book is of general rather than 

 merely local interest, since a large amount of space is given 

 to the consideration of subjects wnich have a general bearing 

 — the peat beds and the evidence they yield as to primitive 

 woodland on the moors, the relationship of the moorland flora 

 and fauna to the glaciation of the district, the origin of various 

 geological features such as outliers and inliers, the general con- 

 ditions determining the existence of moors, the origin of the 

 moorland flora and fauna, and the relations of the moorland 

 fauna to the flora. " The scope of the work," to quote from 

 the author's statement in the introductory chapter, " is to 

 exhibit the interdependence of all aspects of the moors : their 

 antiquities, plants, rocks, insects, stones, birds, and climate 

 form a coherent whole which cannot be fully understood 

 unless all are considered. We shall regard the moors as a 

 unique assemblage of factors of intense interest, which owe 

 their present status to innumerable causes that have been 

 operating for ages. In other words, we shall follow that 

 sequence of events which has led to the evolution of the 

 moorlands of North-Eastern Yorkshire." In this introduction 

 a general account is given of the general physical features and 

 the geology of the district. 



In Chapter I the author discusses the antiquities of the 

 moorland, with some interesting notes on the etymology of the 

 terms " moor," " heath," and so on. On various grounds it is 

 concluded that from early times, perhaps three thousand 

 years ago, the high moors were never clothed with trees. 

 Chapter II deals with the "fat moors" — the typical heather 

 moor, or heath, with a well-developed peat-layer, often of 

 considerable thickness — as contrasted with the "thin moors" 

 considered in Chapter III, where the peat is thin and the 

 different associations are dominated by Calluna, Erica spp.. 

 Scirpus caespitosus, Molinia and Nardus and other heath 

 grasses, Ulex, and so on. Chapter IV is concerned with 

 " mosses" — Sphagnum bog, cotton grass moor (" Eriophore- 

 tum vaginati"), and so on; Chapter V with the moorland 

 slopes, including associations dominated by bracken, birch 



woods, oak-birch woods, larch and pine-woods, bilberry slope, 

 rush bogs with Sphagnum, and so on ; Chapter VI with the 

 interesting " slacks " and " gills " (small valleys with broad 

 flat streamless floors and steep slopes) which often present a 

 remarkable congestion of plant associations, so that many of 

 the types of moorland vegetation may be found within a 

 limited area. In connection with the "slacks" the author 

 gives an interesting summary of recent work on the plant 

 remains in peat deposits in Britain, and concludes that for 

 many thousands of years, probably even since the Ice Age 

 itself, the moors were islands and peninsulas of heath vegeta- 

 tion, surrounded by a great sea of forest and woodland, feelers 

 of which penetrated far into the heart of the uplands along 

 the sides of the streams. This subject is developed more 

 fully in Chapter VII, which is devoted to the geological effects 

 of the Ice Age on the moors, with an account of Professor 

 Kendall's investigations on the former glacier lakes of the 

 district. 



The origin of the moorland flora is next discussed (Chapter 

 VIII), and the conclusion reached is that the geological 

 history and geographical distribution of the chief moorland 

 plants proves that the moors were formed in pre-Glacial times, 

 probably towards the close of the Pliocene period. This 

 leads to a further discussion in Chapter IX of the Ice Age and 

 the moorland flora, the history of the latter being summed up 

 in the following stages: (1) Evolution of Vaccinium spp., 

 Eriophorum, Empetrum, and so on, in a northern land in 

 Pliocene times, and a gradual dispersal of these species south- 

 wards with the approach of the Ice Age ; (2) origin of Calluna 

 and Erica spp. in South-Western Europe and their dispersal 

 north and east during the Pliocene period ; (3) advent of the 

 Ice Age with survival of most of the northern species on the 

 driftless area — Erica cinerea, E. Tetralix, Myrica Gale, 

 and Pteris aquilina, however, probably driven from the 

 district ; (4) post-Glacial re-entrance of these four plants, and 

 development of moors from the Arctic plant communities of 

 the uplands and upon the bare ground ; (5) a warmer and 

 drier climate with a decline of wet moors and the growth of 

 trees in the slacks, gills, and dales and on slopes and parts of 

 the higher moors ; (6) an increased rainfall with an accelera- 

 tion of moor formation, and a destruction of the birch and 

 oak woods in the slacks and gills by the development of peat 

 bogs ; (7) the present moors, where peat formation and 

 destruction counterbalance each another. 



Then follow four chapters of mainly geological interest, 

 and the work concludes with three extremely interesting and 

 suggestive chapters on animal life (in particular insect life) on 

 the moors, containing the results of the author's patient and 

 successful investigations in a field which has been com- 

 paratively little worked at, and a finely written general 

 conclusion, in which the author skilfully gathers up the 

 threads of the work and emphasises the importance of his 

 main theme — the interdependence of the various factors 

 which condition the moorland climate, physiography, flora, 

 and fauna. Extensive tables are appended, giving the chief 

 facts regarding the moorland lepidoptera divided into two 

 groups according to whether the food plants are Calluna and 

 Erica or Vaccinium. This portion of the book forms a 

 mine of information concerning the insect fauna of moor- 

 lands and its relation to the flora. 



There are two large maps coloured to show the geological 

 formations and the distribution of moorland respectively in 

 north-east Yorkshire,' and a map of typical geological sections. 

 Of the photographic plates with which the book is lavishly 

 illustrated all are excellent and many are particularly fine. 

 This book will certainly rank as a standard work on British 

 vegetation, and it is to be hoped that the successful publica- 

 tion of a work of this scope will be followed by the production 

 of other books dealing in a similar manner with the vegetation 

 of larger or smaller areas of the British Isles. 



By the courtesy of the publishers we reproduce here two 



of the plates illustrating Mr. Elgee's work (see Figures 



235 and 236). 



F. C. 



