January 8, 1897.] 



SCIENCE. 



65 



iiflora, described on p. 397, is the same 

 as S. juneiformis Engelm. & Gray, described on 

 page 400. Bouteloua ramosa Scribn. is described 

 on page 416, and again on page 418 it appears as 

 a variety of Bouteloua oligostachya. Leptochola 

 polygama (Foiirn.), described on page 437, is the 

 same as Gouinia polygama Fourn., a species 

 identical with Bromus virgatus Presl. Gouinia 

 appears to be a well established genus, and the 

 grass in question should be named Gouinia vir- 

 gata (Presl). Eragrostis imllida Vasey, de- 

 scribed on page 479, is not distinct from E. 

 glomei-ata (Walt.), E. conferfa Trm., described on 

 page 481, but it is very unlike Ergroastis alba 

 Presl, the type of which has been seen by the 

 writer. Under Atropis fendleriana (Steud.) is in- 

 cluded under Poa arida Vasey, which is a distinct 

 and well marked species, as are Poa eatoni S. 

 Wats, and Poa lueida Vasey, also cited as syno- 

 nyms, although the latter is very close to Poa 

 buckleyana Nash. Atropis Icevis (Vasey) is, as 

 stated, Poa lasvis Vasey, but that name should be 

 changed to Poa Isevigata. ' Fesluca rubra var. 

 pubescens Vasey ined.' is the same as Bromus 

 secundus Presl, and Fesluca richardsonii Hook., 

 Bromus barbatoides Beal, page 614, is Bromus 

 trinii Desv. Eamaley, and not R. Pound, ought 

 to be cited after Agrojyyron violaeescens on page 

 635, and after Agropyron caninoides on page 

 640. Agropyron violaeescens is Agropyron rich- 

 ardsoni Schrad. ^Agropyron glaucum (Desf.),' 

 page 637, is Agropyron spicatum (Pursh). Poa 

 brandegei Scribn. in herb.,' page 544, is the 

 same as Poa lettermani Vasey, described under 

 Atropis on page 579. Under Atropis pringlei 

 (Scribn.), page 578, Poa pattersoni Vasey is er- 

 roneously cited as a synonym. 



There are keys to the genera under all the 

 tribes with the exception of Hordese, and there 

 are also keys to the species under the genera. 

 The difiiculty of making keys is appreciated by 

 all who have undertaken them, and the value 

 of good keys is at once appreciated by those 

 having occasion to use them. A clear concep- 

 tion of all the species of a genus, and a suffi- 

 cient knowledge of their characters to be able 

 to express briefly their most obvious points of 

 difference or resemblance, is essential to the 

 compilation of a good key. The test of a key 

 of analj'sis is in its use. The writer has not 



attempted to use the keys in the work under 

 notice, but it is evident that they have been 

 prepared with much labor and painstaking care. 

 In glancing them over one is struck by the very 

 frequent use of measurements of glumes, awns 

 or ligules, the dimensions of which are often 

 too slight or too inconstant to be of much value 

 in a diagnosis. 



On page 287, under Muhlenbergia, in a con- 

 siderable series of ' g,' there are: 



g. Floral glume 2.5 mm. long, ligule 2-2.5 mm. 



long, awn 1 mm. long 23 



g. Floral glume 2-2.7 mm. long, ligule 2-3 mm. 



long, [awn] 1-3 mm. long 24 



Lower down on the same page, in a series 

 'h,' appears: 

 h. Floral glume 3.5 mm. long, ligule 1 mm. long, 



awn 10-15 mm. long 33 



h. Floral glume 3.5-2.5 mm. long, ligule 1 mm. 



long, awn 10-15 mm. long 28 



These distinctions are too slight to be of 

 much assistance to the student in running down 

 a species. 



Considering the extent of the work and the 

 conditions under which the author labored, it 

 is remarkable that more errors have not occur- 

 red. In spite of the faults to which attention 

 has been called, and others not noted, due, 

 chiefly, to imperfect proof-reading — the diificul- 

 ties of which in such publications few appre- 

 ciate^the work is one of much value to syste- 

 matic botanists, and indispensable to those en- 

 gaged in the study of the large and very inter- 

 esting family of plants treated. 



F. Lamson-Sceibnee. 



Race Traits and Tendencies of the American Negro. 

 By Feedeeick L. Hoffman (Publications of 

 the American Economic Association, Vol. XI., 

 Nos. 1, 2 and 3. August, 1896. Pp. 1-329). 

 The Macmillan Company. Paper, $1.25 ; 

 cloth, $2.00. 



This work is a mine of statistical information 

 relating to the population, viability, anthropo- 

 metry, and the racial, social and economic con- 

 ditions of the negro in the United States and 

 incidentally in the West Indies; and the figures, 

 culled with evident care from the most trust- 

 worthy sources and collected through personal 



