376 Floristik, Geographie, Systematik etc. 



length of the germination period and the final germination per 

 Cent. Light plays absolutely no part in the germination of tree 

 seeds. Xerophilous species begin germination first, xero-mesophilous 

 germinate last. 



As far, as height growth goes, it is evident that pines on 

 account of their greater drought resistance, may grow as well in 

 sand or gravel, or even attain a greater height in sand, or gravel, 

 than in loam. That root development is greatest in gravel is due 

 undoubtedly to the fact that water percolates through this soil and 

 hence the roots have to go deep for the moisture. 



Under the third head the relation of size and weight of seed 

 to germination and early development, for example, out of the 

 numerous tests made, Boerker finds that large seeds of Pinus pon- 

 derosa and Pseudotsuga taxifoUa produce a higher final germination 

 per Cent than small seeds. The Rocky Mountain varieties of Pinus 

 ponderosa produce smaller seeds, their germination begins earlier, 

 their germination period is shorter, and their germination curves 

 rise much more rapidly in the case of the Pacific Coast varieties 

 of this species. Harshberger. 



Braun, E. L., The Physiographic Ecology of the Cincin- 

 nati Region. (Ohio State Univ. Bull. XX. p. 115— 211. June 1916.) 



This paper with bibliography is illustrated with 58 figures 

 representing maps and photographs of the Vegetation. It deals with 

 the Vegetation of the region as related to its physiograph5^ The 

 forest associations and Clearing associations of the upland series 

 are first considered with reference to the depressions, undrained 

 flats, morainial materials of the surface. The vegetal covering of 

 the ravines, river bluffs of the slope series are next described 

 followed by a similar account of the terraces, filled Valleys and 

 flood piain series. She finds that soil influences may be overcome 

 by topographic conditions. Dissimilar topographic forms, in the 

 same soil are occupied by different plant associations. 



Harshberger. 



Campbell, D. H., Plant Distribution in California. (Scien- 

 tific Monthly. p. 209—225. 13 figs. March 1916.) 



The author deals with the geographic position of California, 

 the climate and topography of the State as related to its Vegetation. 

 He contrasts the difference between certain floras, as the dense 

 redwood forests of the north, the flora of the Colorado and Mo- 

 jave deserts, and the slopes of the Sierra Nevada mountains. 

 The chaparral districts of the State are considered, as well, as 

 other characteristic features. Harshberger. 



Dahl, O., Botaniske undersökelser i Helgeland [Botani- 

 sche Untersuchungen in Helgeland]. II. Med. et Tilläg: 

 De Sorbo Arranensis Hedl. et affinibus homozygoticis 

 Norvegiae. Auetore T. Hedlund. (Videnskapsselskapets Skrif- 

 ter. I. Mat. Naturv. Kl. 1914. N« 4. IV, 184 pp. und 3 Tafl. Kristia- 

 nia 1915.) 

 Verf. hat floristische Untersuchungen in Nordland zwischen 

 65—66° n. Br. in einer Gegend, welche früher nur wenig erforscht 

 war, ausgeführt. Zuerst giebt Verf. eine kurze Mitteilung über die 



