CURRENT LITERATURE 



BOOK REVIEWS 



The living cycads 



In a recent volume of the ''University of Chicago Science Series" Cham- 

 berlain' presents in untechnical language some of the results of his 15 years 

 of study on cycads. This group of 9 genera has several advantages from 

 the point of view of popular treatment, and of these the writer makes 

 good use. It may safely be said that no one is so well fitted as the author 

 to deal with this subject, because he approaches the task not only as an expert 

 student of the group, but also as one who knows the cycads as living plants, 

 on account of his extended travel in regions where cycads occur. The title 

 of the book was selected, so the author tells us, to contrast with Wieland's 

 The fossil cycads. 



The account is divided into 3 sections, part I dealing with the collecting 

 of the material, part II with the hfe history, and part III with the evolution 

 and phylogeny of the group. The first part recounts the author's journey- 

 ings in the 3 cycad regions, tropical America, Australia, and South Africa, 

 but is much more than a narrative, for it includes important observations 

 taken in the field which help to clear up certain disputed points. This part 

 is rendered attractive by the author's excellent photographs of field speci- 

 mens as well as by his graphic style, and will probably be the most interesting 

 section to the non-botanical reader. The section on life history includes a 

 short chapter on vegetative structures, in which the vascular tissues receive 

 scant attention. The very significant anatomical features were probably 

 considered too technical for presentation to a general audience. The sporoge- 

 nous and gametophytic structures, which have attracted so much attention 

 to the group, are clearly described and figured, and are compared with the 

 corresponding structures of ferns. It is in this part of the book that the 

 author's particular contribution to our knowledge of cycads comes out con- 

 spicuously. One realizes how many gaps in the story have been filled during 

 the past decade. Part III, the shortest in the book, passes on from fact to 

 speculation, and brings the ferns and fossil cycads into relation with the living 

 cycads. Especially satisfying is the account of the evolution of the cone, 

 which presents a remarkable series even in living genera. The point of view 

 throughout this section is a conservative one, as is evinced by the treatment 

 of Bennettitales and their relationships. 



'Chamberlain, Charles J., The living cycads. 8vo, pp. xiv-|-i 72.- _/zg5. gi. 

 The University of Chicago Press. 1919. 



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