.abstracts: botany 607 



GEOCHEMISTRY. — Quality of the surface waters of Oregon. Walton 

 Van Winkle. U. S. Geological Survey Water-Supply Paper 363. 

 Pp. 1137 1914. (Prepared in cooperation with the state of Oregon, 

 John H. LEwqs, State Engineer.) 

 This document embodies the results of the first comprehensive study 

 of the quality of the surface waters of Oregon and reports serial analy- 

 ses of water from 20 stations on the principal rivers with a discussion 

 of the analyses in relation to conditions of geology, climate, and eco- 

 nomic development. The investigations of the composition of saline 

 lake waters in southeastern Oregon indicate that the commercial recov- 

 ery of soda salts from few of them is practicable. Most of the streams 

 within the State drain regions of basalts and other effusives, and con- 

 sequently carry relatively little mineral matter in solution. 



R. B. Dole. 



GEOCHEMISTRY. — The constitution of the natural silicates. Frank 

 WiGGLESWORTH Clarke. U. S. Geological Survey Bulletin No. 

 588. Pp. 128. 1914. 

 This bulletin is essentially a revision, brought down to date of bulle- 

 tin No. 125. It gives a more complete discussion of the silicic acids, 

 and develops more completely than in the former edition the conception 

 that the complex alumosihcates are best formulated as substitution 

 derivatives of normal silicates of aluminum. F. W. C. 



BOTANY. — A conspectus of North American firs, exclusive of Mexico. 

 W. H. Lamb. Proceedings of the Society of American Foresters, 

 9. Pp. 528-538. October, 1914. 



This is a dendrological monograph on North 'American species of 

 Abies, exclusive of Mexico, designed especially for the information of 

 forest officers. 



In our native firs, generally regarded as difficult to distinguish, each 

 specific form is here definitely separated from its nearest relative by 

 some anatomical difference. Those characteristics which are so variant 

 as to be valueless as a means of identification are discarded, and the 

 form of the cone-bract, the arrangement of the leaves, the character 

 of the upper surface of the leaves, and the position of the resin ducts 

 in the leaf are considered as the determinative factors so far as our 

 native firs are concerned. 



The firs, as far as they can be distinguished from foliage alone, are 

 outhned in a key based entirely upon leaf differences, and a complete 



