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NOTICES OF NEW BOOKS. 



The Living Cycads. Bj Charles Joseph Chamberlain. Small 8vo, 

 xiv and 172 pp., 91 figs. Chicago : University Press. 1919. 

 Price $1.50. 



This little volume is one of the University of Chicago Science Series, 

 which aims to fill a position between the technical journal with its short 

 articles and the elaborate treatise. The volumes will confine themselves 

 to specific problems of current interest, and will be written not only for 

 the specialist but for the educated layman. The Cycads are a family 

 of special interest to the botanist, representing as they do the survival 

 of a line which may be traced through Mesozoic to Palaeozoic times, 

 and the chapters dealing with their occurrence and distribution on the 

 earth's surface at the present day, written in the form of a traveller's 

 tale, should certainly appeal to the educated layman ; the later chapters 

 on structure and evolution require some knowledge of botany if they 

 are to be read with profit. The author, Prof. Chamberlain, is eminently 

 fitted for the task of presenting an account of the family. For fifteen 

 years he has been investigating the various genera and species, and has 

 studied them in their native homes in Mexico, Cuba, Australia and 

 Africa. The first part of the volume is an admirable account, illustrated 

 by excellent photographs, of their distribution, method of growth and 

 environment, and provides an object lesson which might well be followed 

 by workers in other groups. Botanists who are inclined to regard the 

 Cycads as a decadent family will learn with some surprise of the fre- 

 quency of some of the species in their own special locality, as, for 

 instance, Boweiiia, at Cairns in Queensland, growing in thousands and 

 forming a prominent feature of the scanty Eucalyptus forest. Anotlier 

 Queensland genus, 31acrozamia, the tallest of the family {M. Hopei may 

 reach a height of 60 feet) is also found in- considerable numbers. 

 Microcycas, on the other hand, confined to Cuba, is represented only by 

 comparatively few individuals of a single species. Though generally in- 

 significant in size, compared with other trees, the Cycads are remarkably 

 long-lived. A Dioon, with a trunk not more than 1 foot in diameter 

 and 6 feet in height, may have reached the age of 1000 years. Age is 

 determined not by counting annual rings of growth of wood as in 

 deciduous trees, but by study of the armour of leaf-bases which persist 

 round the trunk, a definite number of leaves being developed in each 

 season of growth. 



Part II. is an account of the life-history, and deals successively with 

 vegetative structures, reproductive structures, fertilization, and the 



