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SCIENCE 



[N. S. Vol. XLVII. No. 1204 



of papers have been piiblislied with, almost 

 equal lack of precise and attested knowledge 

 of the identity of the form treated. 



Of course some workers are more careful 

 than others. E. B. Wilson seems to me to be 

 a man who wishes to know exactly what he is 

 working with. The same may be said for 

 J. T. Patterson and for S. I. Kornhauser and 

 others, but on the whole I think that this 

 suggestion is worth while and I hope that it 

 will appeal to many. 



L. 0. Howard 



SCIENTIFIC BOOKS 



The Anatomy of Woody Plants. By Edward 

 Charles Jeffrey. University of Chicago 

 Press, Chicago. October, 1917. With 306 

 illustrations. Pp. x + 478. Price $4. 

 This work, by the well-known professor of 

 plant morphology in Harvard University, has 

 been expected with much interest. The ex- 

 pression in the Preface, "Woody or so-called 

 vascular plants," suggests that the two terms 

 are synonymous, and, as a matter of fact, 

 herbaceous forms are by no means neglected, 

 though special prominence is given to the 

 woody types, in accordance with the author's 

 belief in their primitive nature. 



Great stress is laid throughout on the sup- 

 posed " Canons of Comparative Anatomy " 

 formulated in Chapter XVII. It is even 

 stated in the Preface that " any conclusions 

 not in harmony with them have ordinarily 

 not been considered " (with certain excep- 

 tions). This at once indicates the highly de- 

 ductive character of the treatment, though the 

 word " induction " is often used. The book, 

 in fact, is essentially an able exposition of the 

 views of Professor Jeffrey and his school; it 

 will therefore be read with the most advan- 

 tage by those who are in a position to read 

 critically. 



The general plan of the book is as follows : 

 After a short chapter on the cell, we come 

 to the tissue-systems. Next follows a chapter 

 on wood in general, succeeded by fo-ur on the 

 secondary wood and one on the phloem. The 

 epidermis and the fundamental tissues occupy 

 Chapters IX. and X. Then we have a chapter 



on the definitions of the organs, succeeded by 

 three on the root, stem and leaf, respectively. 

 Then follow two chapters, which it is a wel- 

 come surprise to find in an anatomical text- 

 book, on the microsporangium, and on the 

 megasporangium and seed. We then arrive 

 at the important Chapter XVII., which lays 

 down the author's " Canons of Comparative 

 Anatomy." The arrangement of the next 

 twelve chapters is systematic, from the Lyco- 

 podiales to the Monocotyledons. Chapter 

 XXX. is an anatomical structure and climatic 

 evolution ; Chapter XXXI. treats of the evolu- 

 tionary principles exhibited by the Composi- 

 tae, and the last chapter is devoted to ana- 

 tomical technique. The arrangement involves 

 a certain amount of repetition, which, how- 

 ever, serves to bring out the points on which 

 the author desires to lay special stress. 



In defining the tissue-systems the author 

 returns to Sachs's old divisions, the epidermal, 

 fibrovascular and fundamental systems. The 

 stele, so prominent as an anajtomical unit in 

 the work of the last quarter of a century, thus 

 disappears; it is rarely mentioned and is not 

 to be found in the index. This striking rever- 

 sion in terminology is intimately connected 

 with the author's theory that the pith is of 

 common origin vsdth the cortex and so does not 

 belong to the central cylinder. 



Much attention is given to the wood (espe- 

 cially the secondary wood) as this is the 

 tissue for which the best fossil evidence is 

 available; The libriform fibers are derived 

 from tracheides, not from parenchyma as 

 Strasburger held. Evidence is given also for 

 the origin of xylem-parenchyma and of the 

 so-called medullary rays from tracheides, and 

 some excellent new figures of Lepidodendroid 

 structure are furnished, in support of this 

 view. 



The statement (p. 49 and elsewhere) that 

 tangential pits are absent in Palseozoic woods, 

 is erroneous ; they have long been described in 

 Pitys antiqua and also occur in Mesoxylon 

 multirame and doubtless in other species. In 

 Chapter VII. there is an excellent compara- 

 tive account of xylem-vessels in Gnetales and 

 Angiosperms. 



