104 THE JOURNAL OF BOTANY 



which are in themselves sufficient to make the book a treasured 

 possession ; the treatment and colouring of the flowers and buds 

 leave nothing to be desired— the green of the leaves is, we 

 think, a little monotonous. The woodcut figures in the text 

 are excellent, and Miss Cardew's figures of the seeds (which 

 strike us as unnecessarily large) are admirably executed. 



No assurance is needed as to Mr. Dykes's competence to speak 

 with authority on all that concerns Iris cultivation ; the fact that 

 he has grown nearly all the species he describes is sufficient 

 testimony to his skill as a gardener, and the observations scattered 

 through the book, as well as his excellent introduction, show that 

 he has adequately considered the bearings of the results of his 

 experiments in growth upon the question of the limitation of 

 species. He has, whenever possible, procured plants or seeds 

 from the localities whence the types of the species were obtained ; 

 " seedlings of as many species as possible have been raised in 

 order to determine the limits of their variability ; " "in analyzing 

 the results thus obtained, it has been impossible to avoid feeling 

 how utterly the Mendelian laws have shaken the basis on which 

 our ideas as to what constitutes a species were founded." As a 

 result of his experiments and investigations the number of species 

 recognized by previous monographers of the genus has been 

 largely reduced, and relationships have been pointed out which 

 may eventually lead to further reductions. The descriptions, 

 evidently from living plants, are detailed and elaborate, although 

 one notes in them just that absence of detail which in other 

 respects mars the book; thus on p. 116 we read "filaments 

 short, anthers longer than the filaments," and on the opposite 

 page "filaments" [followed by a space], "anthers longer than 

 the filaments" — no measurements being given in either case. 



So far, however, the book is satisfactory enough, but it is to 

 be regretted that in its botanical aspect it is open to criticism 

 which a greater familiarity with modes of book -preparation would 

 have rendered unnecessary. Mr. Dykes acknowledges " invaluable 

 hints as to method" from Dr. Stapf ; these, however, if sufficient, 

 can hardly have been acted upon, for we do not remember to 

 have seen a work of equal importance from which satisfactory 

 "method" has been so entirely absent. We are at a loss to 

 understand how the Cambridge University Press, with a com- 

 petent man like Dr. Moss always at hand, can have allowed 

 itself to issue a volume in which the aid of typography to the 

 intelligent presentment of the text is so conspicuously ignored ; 

 this criticism, which no one who opens the volume and who 

 knows how books should be produced will consider too severe, 

 wo propose to justify later ; at present we confine ourselves to 

 the botanical and literary aspect of the volume. 



We may preface our comments by saying that we have been 

 through Mr. Dykes's book with the care to which its importance 

 entitles it, and have noted for discussion a number of points 

 upon which space will not allow us to dwell. 



At the outset we note a certain absence of arrangement in 



