528 



NATURE 



[July 24, 191; 



more than any of your sons would have thought 

 possible. 



To the presbyopic eye, looking backward over 

 I he dim years, it seems that it must have been the 

 people of "J.'s" type in Cambridge who have 

 really counted in the revolution of the nineteenth 

 century. "All the world's a stage," and a born 

 stage-manager has, perhaps, as much to do with 

 the success of a play as the "stars" themselves. 



THE FLEUR-DE-LYS. 

 The Genus Iris. Bv W. R. Dykes. With Forty- 

 seven Coloured Drawings by F. H. Round, One 

 Coloured Plate of Seeds by Miss R. M. Cardew, 

 and Thirty Line Drawings by C. \Y. Johnson. 

 Pp. 245. (Cambridge University Press, 1913.) 

 Price 61. 6s. net. 



NO more fitting tribute could have been pre- 

 pared to the memory of Sir Michael Foster 

 than a monograph of the group of plants he loved 

 so well and studied with so deep an interest, and 

 the volume produced by Mr. Dykes would without 

 doubt have evoked Sir Michael's warmest approba- 

 tion. 



The genus Iris, like Crocus and so manv other 

 monocotyledonous genera, offers a particularly fas- 

 cinating field of study from the beauty of form and 

 colour displayed and the remarkable diversity of 

 the species. Mr. Dykes is to be congratulated in 

 having cultivated the majority of the species in his 

 own garden, and with such success that the illus- 

 trations, with but one exception, have been pre- 

 pared from the plants grown by him at Godalming. 

 These illustrations, by Mr. F. H. Round, are 

 elegant works of art which have been very faith- 

 fully reproduced in colour, and form a valuable 

 addition to the volume. The Cambridge Press 

 deserves a special mention in this connection, both 

 for the beauty of the plates and for the style in 

 which the monograph has been published. 



Mr. Dykes has spared himself no pains in 

 searching English, Continental, and American 

 herbaria for his material, and, in particular, Kew, 

 with its herbarium and library, proved to be a 

 mine of wealth. He has wisely studied the type 

 specimens with the original descriptions of all 

 the " species " of Iris, and has thereby been able 

 to arrive at a definite idea as to the actual number 

 of such " species " as are really worthy of specific 

 rank. By ignoring the records of species in local 

 floras, unless they could be verified by actual 

 specimens, Mr. Dykes may have left some gaps 

 in the distribution tables of some of the species, 

 but he has certainly avoided many possible sources 

 of error. 



NO. 2282, VOL. qi] 



Irises are not only plants of interest to the 

 gardener, but they are also of interest to the 

 plant-breeder for the facility with which they may 

 be hybridised. In this direction the late Sir 

 Michael Foster was, of course, an expert, and the 

 hybrids he produced were always a source of the 

 keenest pleasure to him. 



In addition to the ease with which hybridisation 

 may be effected, variation is also characteristic 

 of many species, and it is owing to this tendency 

 that so much confusion as to the limits of species 

 has arisen. Mr. Dykes has constant occasion to 

 allude to this fact, for not only do the plants vary 

 in their wild state, but they show themselves par- 

 ticularly prone to manifest variations under 

 cultivation. Mr. Dykes, however, has been in no 

 hurry to rush to conclusions, but has taken time 

 thoroughly to digest the mass of material which 

 he has studied, and botanists, we feel sure, will 

 agree that they owe him a deep debt of gratitude 

 for the sound and careful work he has done. 



The early pages of the monograph are occupied 

 by general matter dealing with the literature of 

 the iris, structure, distribution, and cultivation, 

 followed by outlines of the different sections of 

 the genus. The species are then described very 

 fully under their respective sections, with full cita- 

 tions of specimens and detailed setting-out of 

 their geographical distribution, followed by useful 

 notes on the affinities of each species. 



It is not possible to attempt any criticism of this 

 the essential part of the book, and its merits can 

 only be adequately realised by one working over 

 the material. It may, however, safely be said 

 that Mr. Dykes has produced a work with much 

 care and sound judgment, the value of which will 

 increase as years pass by. 



THE CHEMISTRY OF FATS AND ALLIED 



SUBSTANCES. 

 Cliemie der Fette, Lipoide und Wachsarten. By 



Dr. \Y. Glikin. Erster Band: pp. xvi + 789 ; 



Zweiter Band: pp. xi + 788. (Leipzig: 



Gebruder Borntraeger, 1913.) Price, 2 vols., 



72 marks. 



A NOTABLE feature of this work is the 

 amount of consideration given to the 

 physiological chemistry of the fats, and to the 

 general chemistry of the lipoids. The question 

 of the origin of fat in the animal body is of much 

 interest and importance ; and in the earlier 

 chapters of the first volume Dr. Glikin gives an 

 account of the experimental evidence on which 

 arguments have been based to show that the fat 

 of the animal body may be produced from fat 



