December 25, 1919] 



NATURE 



411 



parts. Part i., "Collecting the Material," gives 

 an eminently . readable account of the different 

 genera and species in their homes, illustrated by 

 some excellent photographs. It will interest the 

 educated layman as well as the botanist. Part ii., 

 "The Life History," is a concise account of the 

 Cycads in their various stages, including vegeta- 

 tive structures, reproductive structures, fertilisa- 

 tion, and the embryo and seedling. It is written 

 with great clearness and is also well illustrated, but 

 the mere educated layman will not get far beyond 

 the first chapter. In part iii., "The Evolution and 

 Phylogeny of the Group," we pass from the record 

 of fact to speculation. This will interest the 

 botanical student, who will follow easily at any 

 rate the development of the different types of 

 female sporophyll from the 'foliage-leaf, while he 

 will be struck with the comparative uniformity of 

 the male cone throughout the group. The evolu- 

 tion of the gametophyte and of embryogeny 

 presents greater difficulty. Botanists will look 

 forward to reading the much more extended tech- 

 nical account of the living Cycads on which the 

 author has been at work for many years ; and the 

 results of this work will be of the greatest interest 

 to those who are investigating the evolution and 

 phylogeny of the Gymnosperms. 



(3) Mr. Crabtree's little book on the British 

 ferns makes a delightful introduction to their col- 

 lection and study. The habitat and form are 

 described in twenty-eight species (about three- 

 fourths of the British species), and each descrip- 

 tion is accompanied by a full-page photographic 

 reproduction of the plant as it grows and of a 

 portion of a fertile leaf showing the sori on the 

 pinnffi. The latter are sometimes wanting in clear 

 definition. An introduction gives a very brief 

 account of the life-history of a fern, and also 

 directions for collecting, drying, and mounting. 

 The author recommends mounting in a book. 

 This was the custom in the old herbaria, but the 

 plan of mounting on separate sheets which may 

 be kept in a box or portfolio is much to be pre- 

 ferred. It allows intercalation of additional speci- 

 mens or replacement of old ones, as well as altera- 

 tions in arrangement, all of which are imprac- 

 ticable with the book-form. 



OVR BOOKSHELF. 

 Ireland: The Outpost. By Prof. Grenville A. J. 

 Cole. Pp. 78. (London : Oxford University 

 Press; Humphre)' Milford, 1919.) Price 

 3s. 6d. net. 

 A BRAVE and poetic effort is here made to present 

 ■\hat V'idal de la Blache would call the personality 

 if Ireland. The countrv is viewed as an outpost 

 of Eurasia, from which her people and her civilisa- 

 tion have been derived in successive and over- 

 lapping waves. Prof. Cole's name assures the 

 picturesque interest of the structural sections, and 

 the maps and views are most helpful. .-\ laudable 

 ■effort is also made to set forth the present state 

 of the problem of the peopling of Ireland, and 

 this chapter is a welcome change from the too 

 common fanciful remarks about Celts. No two 

 NO. 2617, VOL. 104] 



writers would make the same sketch on this 

 subject, and several would dissent from Prof. 

 Cole's identification of the archasologically named 

 Beaker folk with the " Bronze age " invaders of 

 Ireland and with the monuments of New Grange. 

 Nevertheless, Prof. Cole has made a suggestive 

 summary that may well make a basis for discus- 

 sion. The very short mention of Roman times 

 and of the days of the saints is a little disappoint- 

 ing perhaps, as the story of those days emphasises 

 the initiative of Ireland. 



Separate accounts of the barrier of Leinster and 

 the Irish plain, the uplands of the north and the 

 Armorican ranges of the south, are full of interest 

 with many a picturesque phrase and much fine 

 human sympathy. The section on exits and en- 

 trances and communications hints at future de- 

 velopments of train ferries and of trans-.\tlantic 

 services from the West, while it gives a fresh 

 criticism of the railwav system. 



The book should promote a more sympathetic 

 understanding of Ireland's problems, and must 

 be useful to the student and teacher, as well as 

 to the general bodv of British citizens. 



H. J. F. 



British Rainfall, 1918. On the Distribution of 

 Rain in Space and Time over the British Isles 

 during the Year igi8. By Hugh Robert Mill 

 and M. de Carle S. Salter. The Fifty-eighth 

 Annual Volume. Pp. 242. (London : Edward 

 .Stanford, Ltd., 1919.) Price los. 

 TAnuLAR matter of great precision and of con- 

 siderable scientific value as recorded by about 5000 

 observers constitutes the bulk of the information 

 set out in this volume. The British Rainfall 

 Organisation is to be congratulated on the high 

 standard of the work which for the last time is 

 produced under practically private management. 

 Dr. H. R. Mill, after acting as director of the 

 Organisation for nearlv twenty years, has given 

 over the control, which has now passed to the 

 Meteorological Office. 



An article on the development of the British 

 Rainfall Organisation since 1910 shows con- 

 siderable activity in the production of rainfall 

 maps. A series showing the annual rainfall of 

 the British Isles from 1865 to 1914, on a scale of 

 nineteen miles to an inch, has been completed. 

 A map on the scale of half an inch to a mile, 

 showing the relation of rainfall to geographical 

 features, is stated to be in contemplation. 



Mr. Carle Salter contributes an article on "The 

 Relation of Rainfall to Configuration," and he 

 deals with the physical processes of rain forma- 

 tion. 



Raijifall maps are given for each month, show- 

 ing the actual fall in inches and the percentage 

 of average. A coloured map shows the 

 relation of rainfall in igi8 to the average of 

 1875-1909. The rainfall was more than 30 per 

 cent, above the average in Merionethshire, Central 

 and North Lancashire, North Dumfries.shire, and 

 part of CO. Kerry. The areas of deficient rainfall 

 durine tqiiS occurred chieflv in the east of Great 

 Britain. C. H. 



