240 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



BOOK REVIEWS. 



" The Genus Iris." By W. R. Dykes. Fol., 245 pp., 48 coloured 

 plates. (University Press, Cambridge.) 6 guineas net. 



This monograph has been looked forward to for some time, and 

 expectation will not be disappointed. A few months ago Mr. Dykes 

 published an admirable little book on Irises in the " Present-Day 

 Gardening " series, which gave a deal of information in a compact and 

 inexpensive form, and at the same time showed him to be excellently 

 equipped with knowledge and personal experience for this larger task. 

 Indeed the only complaint that can be made of the sumptuous 

 volume before us is as to its price. All gardeners who have an 

 affection for the Iris will wish to possess it, and it is to be hoped that 

 many, beyond whose purse it lies, will have access to it, in order that 

 this wonderfully various genus may become as widely known as the 

 author would wish. Many good gardens can show but a very limited 

 selection of Irises, while those who grow few beyond I. germanica are 

 often heard to complain that their irises are " so soon over," whereas, 

 without attempting the more difficult kinds, such as those of the 

 Oncocyclus, and Californian sections, it is easily possible to have 

 irises in flower in the open for at least eight months of the year. 

 The book is indeed a happy combination of scientific investigation 

 and practical information. The author, following in the footsteps of 

 the late Sir Michael Foster (magnum et venerabile nomen for all lovers 

 of Irises), has proceeded on the very rational assumption that the 

 best way to know the genus is to grow it. Hence, though he has 

 made the fullest possible use of all available herbarium material, he 

 has, whenever feasible, verified everything by observation of the 

 actual life of the plants. To this end he has himself formed a truly 

 remarkable collection, and it is a striking fact that all the plates, 

 save one, were drawn from plants flowered in the open in the author's 

 own garden. 



The gardener will find clear and careful suggestions in the chapter 

 on Cultivation, in the sections at the end of the book on hybridizing and 

 on growing from seed, and at the end of the description of each species. 

 Certain time-honoured heresies about Irises die hard, but it is to be 

 hoped that they are moribund and that Mr. Dykes' authority will 

 help to kill them : e.g., it is still believed by many that autumn is the 

 time for transplantation, that the leaves of " German " irises should 

 be trimmed off short when the beds are tidied up, and that Irises in 

 general are lovers of damp, if not of shade. Presumably this last 

 belief comes from putting together the facts that of the two English 

 species /. Pscudacorus is a water-lover and /. foetidissima is often 



