ABSTRACTS 



Authors of scientific papers are requested to see that abstracts, preferably 

 prepared and signed by themselves, are forwarded promptly to the editors. 

 The abstracts should conform in length and general style to those appearing in 

 this issue. 



BOTANY. — A botanical trip to Mexico. A. S. Hitchcock. Sci. 



Monthly 8: 129-145, 216-338, pis. 34, maps 6. February, March, 



1919. 



An account is given of a trip made in 19 10 for the purpose of study- 

 ing and collecting grasses. A map showing the itinerary indicates 

 that all the states north of the isthmus of Tehuantepec were visited 

 except Sinaloa, Tlaxcala, and the territory of Tepic. There is a dis- 

 cussion of the topography (illustrated by a map), the rainfall (with a 

 table and map showing the annual rainfall at representative stations, 

 a map showing isohyets, a series of maps showing the annual rainfall 

 by months), and the temperature. An account is given of the floral 

 regions, the range conditions, and the forage crops. 



Especial attention is given to the distribution of the grasses in rela- 

 tion to the floral regions, of which the most important are the eastern 

 Coastal Plain, the western Coastal Plain, the Plateau, the slope from 

 the Plateau to the Coastal Plain, the high mountains, and the ponds and 

 marshes. 



Orizaba was ascended to nearly 18,000 feet, Popocatepetl to snowline 

 (about 15,000 feet), and Nevada de Colima to the summit (14,370 feet). 



A. S. H. 



ECONOMICS.— Potoio flour and potato bread. J. A. LeClerc. The 



Potato Magazine. January and February, 1919. 



This article compares the composition of potato and wheat flours 

 and of breads made with a combination of 20 per cent of potato flour and 

 80 per cent wheat flour. It also shows how many pounds of the various 

 food constituents of potato, potato flour, and of wheat flour can be ob- 

 tained for one dollar with varying prices for these products. The 

 amount of food constituents obtained from one acre of land grown to 

 potatoes and to wheat is also given. Bread made with the use of po- 

 tato flour as a part substitute is appreciably richer in mineral constit- 

 uents than is white bread, but somewhat poorer in fat and protein. 



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