iqiq] current literature 479 



of such a fundamental group. In the two chapters assigned to Pteridophytes, 

 only the Lycopodiales and Filicales are discussed. In the two chapters 

 dealing with Bryophytes, students of this group will be surprised to learn that 

 in Hepaticae the sporophyte, "except in the peculiar group Anthoceroteae, 

 does not carry on photosynthesis." A statement concerning the ventilated 

 structures of the gametophyte of Bryophytes is likely to mislead any but 

 intimate students of the group: "In the sporophyte of vascular plants the 

 t)T)ical photosynthetic organ is the leaf blade with its ventilated mesophyll 

 and stomatal control. In the gametophyte of mosses and liverworts a 

 similarly ventilated structure is seen in the leaves of the larger mosses and in 

 the thallus-structure of the Marchantiales. These are, however, parts of the 

 gametophyte, and the ventilated structure is here produced mainly by invo- 

 lution of the outer surface, while in vascular plants it arises from intercellular 

 splitting of the cell walls. The physiological end is the same, in both cases, 

 but the place and means are different. Plainly these are the results of parallel 

 evolution, or homoplasy." Had the actual facts in Marchantiales been stated, 

 the proof of homoplasy would have been absolute. Thallophytes are dealt 

 with in 8 chapters. In the introductory chapter a statement widely applicable 

 to all plant phyla is made: "It must not be assumed that all the organisms 



grouped under a common designation are necessarily akin to one another 



Lines of descent are divergent, and the thallophytes would appear to represent 

 a brush of phyletic lines radiating outwards from some simpler source." The 

 chapter on sex and heredity is presented so clearly, so free from all verbiage, 

 that beginners can easily grasp this subject, usually considered so complex. 

 Likewise, the chapter on alternation of generations, the land habit, and the 

 rise and fall of the gametophyte, is a masterpiece of lucid expression. 



This text is the work of a man notable for brilliant research and also for 

 exceptional power as a teacher. It is an example of the results obtained by a 

 long period of first-hand contact with material as well as the presentation of 

 these results to many generations of students. — W. J. G. Land. 



Forest products 



As the utilization of plant products is a matter of interest to all botanists, 

 a book discussing the use of wood and forest products, other than lumber, 

 should find a place in all botanical libraries. The present volume"! is attrac- 

 tive in appearance, well illustrated, and carefully organized. Some idea of 

 its scope may be obtained from such chapter headings as the following: Wood 

 pulp and paper, Tanning materials. Veneers, Slack and tight cooperage. Naval 

 stores, Wood distillation. Charcoal, Boxes, Cross ties, Poles and piling. Mine 

 timber. Fuel, Shingles, Maple syrup and sugar. Rubber, Dye woods. Excelsior 

 and cork. Under each topic the character and source of the raw material. 



"Brown, N. C, Forest products. 8vo. pp. xix+471. ^g^. 120. New York: 

 Wiley & Sons. 1919. $3. 75. 



