288 Floristik etc. — Angewandte Botanik. 



flora of Central America and the Antilles on former 

 land connections. (Bull. Geol. Soc. Amer. XXIX. p. 649—656. 

 Dec. 30, 1918.) 



"Quercus suggests lack of land connection with North Ame- 

 rica: Nolineae and Yucceae indicate absence of Continental land 

 connection: Phoradendron and Furcraea suggest land connection 

 with North and South America: Agave indicates relationship 

 to a succsssively fragmented Antillean bridge or spur extending 

 southeastward from Yucatan." Trelease. 



Martin, J. N., Botany for agricultural students. (New York, 

 John Willy & Sons. X + 585 pp. 8°. 488 f. 1919.) 



The subject-matter falls under the following topics: The nature 

 and subdivisions of botany, A general view of plants, Flowers, 

 Pistils and stamens, Seeds and fruits, Germination of seeds, Cells 

 and tissues, Roots, Sterns, Buds, Leaves; Thallophytes, Bryophytes, 

 Pteridophytes, Spermatoplnles, Classifications of Angiosperms and 

 some of their families of most economic importance, Ecological 

 Classification of plants, Evolution, Heredily and Plant breeding. 

 Though the chapter clivisions are mainly morphological, the main 

 physiological processes find consideration under one or another 

 of them. Trelease. 



Sampson, A. W„ Climate and plant growth in certain 

 vegetative associations. (U. S. Dept. Agric. Bull. N° 700. p. 

 1—72. f. 1—37. Oct. 1918.) 



Experiments were carried on in the Manti National Forest on 

 the Wasatch mountains in Central Utah using Pisum ar- 

 vense, Triticum durum, und Bromus marginatus as Standard plants. 

 These three species were grown in the oak-brush association at 

 7100 feet altitude, in the aspen-fir association at 8700 feet, and in 

 the spruce-fir association at 10,000 feet and measurements of the 

 physical and climatic factors were made at the three altitudes. 

 Tables and graphs are given to show the relation between the 

 environmental factors and the growth of the Standard plants. The 

 author concludes that the ordinary agricultural crops cannot be 

 grown profitably at elevations exceeding about 8,000 feet. 



W. B. McDougall. 



Sampson, A. W., Effect of grazing upon aspen repro- 

 duction. (U. S. Dept. Agr. Bull. 741. p. 1-29. 7 Textfig. 5 pl. 

 Feb. 1919.) 



The paper is based on five years of study in the Manti Natio- 

 nal Forest in central Utah. Sheep browsing is very much more 

 destructive to young aspen than is browsing by cattle. When aspen 

 forest land is „clean cut" the young shoots grow very rapidty and 

 in three years reach an average height of 45 inches. They are 

 then safe from serious injury by sheep but in the meantime many 

 of them will have been killed by bark eating mammals such as 

 gophers, field mice and rabbits. W. B. McDougall. 



Auaeneeben : 28 October löl» 



Verlag von Gustav Fischer in Jena. 

 Buchdruckerei A. W. Sijthoff in Leiden. 



