Books and Current Literature. 251 



the entire area studied reaches from 5,610 feet (1709 m.) at 

 Samadcn to 13,303 feet (4055 m.) at the summit of Bernina 

 Peak, embracing the drainages of the Bernina and the Roseg 

 rivers, ilie climatological data presented by Riibel include 

 the various phases of temperature conditions; readings of black 

 bulb theremometer in vacuo; percentage of cloudiness; force and 

 direction of v.ind; evaporation during the summer months; 

 humidity; precipitation; soil temperature and light intenstiy. 

 All of these data are presented in such a manner as to show 

 the seasonal march in diiTerent seasons. Many comparative 

 data are given from St. Moritz, Pontresina and Vienna. The 

 evaporation readings are from the Wild instrument, protected 

 from insolation, and largely from wind action. The light in- 

 tensity data were secured by the Wiesner method. At the 

 Hospice of Bernina the temperature extremes are — 9° Fahr. 

 (—23° C.) and 75° Fahr. (24° C), frost being liable to occur in 

 every month of the }ear ;the precipitation is 63 inches (1,600mm.), 

 higher than at any of the low er localities in the vicinity; the evap- 

 oration varied from a monthly minimum of 1.4 inches(36mm.) 

 in August, 1905, to a maximum of 4. 1 inches (104mm.) in August, 

 19i6, being hi her than at \'icnna in the former and lower in 

 the latter summer; the hicrhest mid-day light intensity was to 

 that for Vienna as 6 : 5, the lowest to Vienna as 12 : 1. The 

 vegetation is described under the following principal groups of 

 formations: the coniferous forests of larch and Scot's pine, the 

 tall scrub of pines and alders, the low scrub of Vaccinium, 

 Arciosiaphylos, Jujiiperus and Erica; the moist and dry meadows; 

 the "hochmoor" and "tlachmoor"; the aquatic vegetation and 

 that of the rocks, sand and gravel. The description of the vege- 

 tation is most thorourh-':oing and embraces detailed facts as to 

 the occurrence of every plant association and the vertical limits 

 of the species involved. The numerous illustrations and the 

 very detailed map of the distrihution of the various formations 

 aid in giving a clear portrayal of the botanical aspects of the 

 hirher Al-)s. 



An attempt to determine the entire constellation of cli- 

 matic conditions for a region, and to make also an exact study 

 of the occurence and distribution of its p ant associations and 

 individual species, is an undertaking of no mean magnitude, 



