REVIEWS 165 



independence of the sporophyte may be supposed to be possible, or even likely, 

 considering that in so many fresh-water Algae 1 the zygote undergoes a resting 

 stage, during which the parent plant may die away. 



Sterilisation and the theory of the strobilus, which figure so largely in this book, 

 can only be referred to in a general way. Owing to altering conditions of com- 

 petition and other factors, it is probable that fluctuating changes in size in the 

 sporophyte and its appendages, and in the amount of branching, have always been 

 very generally in progress. In view of such changes, combined with variable 

 requirements of dispersal, it is to be expected that encroachment of the sterile on 

 the fertile region (in the sporophyte or in the plant as a whole), and the converse , 

 may have alternated many times in any direct line of descent. Consequently, 

 evidence relating to these latter phenomena derived from living plants cannot 

 have any great value in an attempt to establish the importance of sterilisation in 

 the far-away ancestors of the Pteridophyta, or in forming a picture of primitive 

 types. 



Different views may be held on many of the theoretical points dealt with, 

 as is fully admitted by the author ; but that is a thing apart from the value of the 

 book, which reaches a high standard of excellence in the nature and amount 

 of the information and illustrations which it contains, and in the thorough and 

 scholarly discussion of the theoretical problems concerned. The author expresses 

 his belief that the full statement of even a speculative view will stimulate inquiry. 

 Apart from the future influence of the book in this direction — and this will without 

 doubt be far-reaching — the work has its own intrinsic value, which needs no 

 apologetics, while the book itself together with the Studies (referred to above) 

 form a good example of the stimulative value of a theory. 



L. A. Boodle. 



Studies in Fossil Botany. Second Edition. Vol. i., Pteridophyta. By Dukin- 

 field Henry Scott, M.A., LL.D., Ph.D., F.R.S. [Pp. xx. + 363.] 

 With 128 illustrations. (London : Adam & Charles Black, 1908 ; price 

 6s. net.) 



The appearance of the first volume of the second edition of Dr. Scott's well-known 

 Studies in Fossil Botany is a matter for congratulation not only to the author, 

 but to all interested in the progress of paleobotany and botany. From the 

 author's point of view, a demand for a further edition after the comparatively short 

 period of seven and a half years must indeed be gratifying. To the public concerned, 

 the revision and extension of the standard work on the subject, and one which 

 more than any other has helped to spread and encourage a knowledge of fossil 

 plants, is equally satisfactory. 



The new Studies differs much from our former " guide, philosopher, and friend " 

 the first edition. When the second volume appears it will be possible to arrive 

 at some measure of the remarkable progress won during the past eight years by a 

 comparison of the two editions. To bring up to date the ground covered by the 

 Studies, as has been done in the second edition, has naturally necessitated ex- 

 pansion. We shall thus not be surprised to find that the new Studies is to appear 

 in two volumes, though we gather that those who do not object to handling a 

 somewhat bulky tome, as this new edition promises to be when completed, will be 

 still able to obtain the work within the limits of a single cover. 



1 It is more probable that the land flora originated from fresh-water forms than direct 

 from marine organisms. 



