PERIODICAL LITERATURE 

 BOTANY AND ZOOLOGY 



Four out of five of the known species of syca- 



Distinguishing more are natives of North America. Brush has 



Characters recently published a detailed description of the 



of three species which occur within the boundaries 



North American of the United States. 



Sycamore Under "Gross structure" is presented a brief 



Woods description of the sapwood and heartwood, of the 



annual rings of growth, and of the pith rays. 

 The color of the sapwood and heartwood and the size of the pith rays 

 are pointed out as being the chief gross and distinguishing characters 

 of the sycamore woods. The avemge weight of the wood and its hard- 

 ness vary but little in the different species and cannot be depended upon 

 as distinguishing characters. 



The writer's study of the minute structure of the wood of the three 

 species appears to show that the pith rays are the only reliable means 

 for identifying the wood of the indigenous species. Viewed in the tan- 

 gential section, the pith rays are broadest horizontally in the eastern 

 and narrowest in the California species; the rays lowest vertically in 

 the eastern and highest in the California species. The rays of the .Ari- 

 zona species are intermediate in character. 



The account of the gross structure and minute anatomy of the wood 

 is followed by an analytical key based on the pith rays. The article 

 closes with an excellent account of the individual characters of each of 

 the native species under the following heads: Distribution. Uses, Gross 

 characters, V^essels. Tracheids, Wood fibers. Wood parenchyma fibers. 

 Intermediate fibers, and Pith rays. The description of the wood of 

 each species is supplemented bv drawings and niicrophotographs. 



J. W. T. 

 Botanical Gazette, Vol. LX1\', Deccmhcr, 1917, pp. 480-496. 



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