August 21, 1908] 



SCIENCE 



239 



SCIENTIFIC JOURNALS AND ARTICLES 



The American Journal of Science, for 

 August, contains the following articles: 



E. T. AiLEN and J. K. Clement : " E5le of 

 Water in Tremolite and Other Minerals." 



G. C. Ashman : " Quantitative Determination 

 of tlie Radium Emanation in the Atmosphere." 



R. W. Langlet : " Determination of Small 

 Amounts of Barium in Rocks." 



W. G. MixTEK : " Heat of Combination of 

 Acidic Oxides -with Sodiimi Oxide and Heat of 

 Oxidation of Chromium." 



I. K. Phelps and L. H. Weed : " Concerning 

 Certain Organic Acids and Acid Anhydrides as 

 Standards in Alkalimetry and Acidimetry." 



I. K. Phelps and L. H. Weed : " Comparison 

 between Succinic Acid, Arsenious Oxide and Silver 

 Chloride as Standards in lodimetry, Acidimetry 

 and Alkalimetry." 



W. E. FoBD and E. W. Tillotson, Je. : " Ortho- 

 clase Twins of Unusual Habit." 



J. V. Lewis : " Palisade Diabase of New 



P. B. LooMis : " New Horse from the Lower 

 Miocene." 



The contents of The AuTc, for July, are as 

 follows : 



E. S. Cameeon : " Observations on the Golden 

 Eagle in Montana." 



J. H. RiLET : " Notes on the Broad- winged 

 Hawks of the West Indies, with Description of 

 a New Form." 



Richard C. Haklow : " Recent Notes on Birds 

 of Eastern Pennsylvania." 



C. J. Pennock : " Birds of Delaware — Addi- 

 tional Notes." 



J. A. Allen : " The Case of 8TRIX vs. ALUCO." 



Edwakd J. Court : " Treganza Blue Heron." 



Francis H. Allen : " Larus kumlieni and 

 other Northern Gulls in the Neighborhood of 

 Boston." 



J. A. Allen : " Columbina versus Chcemepelia." 



James H. Fleming : " The Destruction of 

 Whistling Swans {Olor columbianus) at Niagara 

 Falls." 



Austin Hobaht Clark : " The Macaw of 

 Dominica." 



TYPES OF AMERICAN GRASSES 



Under this title, Mr. A. S. Hitchcock has 



recently published in " Contributions from 



the U. S. National Herbarium," Vol. 12, Pt. 



3, the results of his studies of the tsrpes of 



American grasses described by Linnaeus, 

 Gronovius, Sloane, Swartz and Michaux. 

 These studies were made by Mr. Hitchcock in 

 the spring of 1907, at which time he made a 

 detailed examination of American grasses 

 preserved in the larger herbaria of Europe. 



The contribution is a noteworthy one and 

 will go far toward fixing names for the Amer- 

 ican grasses discussed, not alone specifically, 

 but probably in some cases generically as well. 

 The preservation of grass specimens is in 

 most cases satisfactory as they are little sub- 

 ject to insect depredation. In a large ma- 

 jority of instances, Mr. Hitchcock found the 

 type specimen readily and certainly identifi- 

 able; in some instances where the author had 

 confused two or more species under one, he 

 was obliged to consider each case upon its 

 merits, and he has presented the evidence on 

 which the type specimen was selected by him. 

 In a few of these cases there is opportiinity 

 for difference of opinion, but it seems to the 

 writer that Mr. Hitchcock's decision in such 

 cases should be accepted without further ques- 

 tion in all instances in which he has first 

 designated the type. 



There are a few species which require 

 transposition of names, as for example, Gen- 

 chrus trihuloides L., the type of which proves 

 to be the same as C. macrocephalus (Doell) 

 Scribn. ; the plant which has mostly been 

 known under the name trihuloides should bear 

 the name C. carolinianus Walter; the study 

 brings out a number of cases in which priority, 

 requires the acceptance of earlier published 

 names than those in current use. 



It has been perhaps widely assumed that 

 most of the species of the older authors were 

 more comprehensive in including slightly dif- 

 ferent races than those of recent writers. In 

 some instances this is doubtless true, but in 

 many others the species conception was ap- 

 parently broad only because the describer had 

 but a single specimen, or at best but few to 

 base an opinion upon. Linnasus proposed 

 some species on specimens which have been 

 regarded by some modern authors as belong- 

 ing to the same species, the differences being 

 so slight, while on the other hand he some- 



