DEPARTMENT OF BOTANICAL RESEARCH * 



D. T. MacDougal, Director. 

 The record of the Department for the year shows the completion of some 

 important researches, such as those concerned with the conditions of para- 

 sitism in plants, root-habits of desert plants, the water-balance of succulents, 

 the organization of new work in climatology with the cooperation of Dr. 

 Ellsworth Huntington, the formation of plans for dealing with problems in 

 physiology by chemical methods under Dr. H. A. Spoehr, and the successful 

 prosecution of researches on various correlated topics as described in the 

 following paragraphs. 



THE VEGETATION OF THE SALTON BASIN. 



The general mode of procedure in the revegetation of the bared strands 

 and emersed islands of the Salton Sea having now been determined, a closer 

 analysis of the conditions is being made by physical and chemical methods. 



The changing constitution of the water is clearly illustrated by the follow- 

 ing data furnished by Dr. W. H. Ross, who, in consultation with Prof. R. H. 

 Forbes, has made careful annual analyses of the waters from samples taken 

 early in June at the same location. The third complete analysis of the water, 

 together with the results of the two previous analyses, are given. 



Composition of Salton Sea water. 



Total solids (dried at uo°C.)plus 



water of occlusion and hydration 



Water of occlusion and hydration... 



Sodium (Na) 



Potassium (K) 



Calcium (Ca) 



Magnesium (Mg) , 



Aluminum (Al) 



Iron (Fe) 



Manganese (Mn) 



Zinc(Zn) 



Lead(Pb) 



Copper (Cu) 



Lithium (Li) 



Chlorine (CI) 



Sulphuric (S0 4 ) 



Carbonic (CO3) 



Silicic (Si0 4 ) 



Phosphoric (P0 4 ) 



Nitric (N0 3 ) 



Nitrous (NOo) 



Oxygen consumed 



Boric acid 



Parts in 100,000. 



June 3, 1907. 



364. So 



111.05 

 2.29 

 9-95 

 6.43 

 0.030 

 0.005 



None 



None 



None 



May 25, 1908. 



437-20 



134.26 

 2.78 

 11.87 

 7-63 

 0-35 

 0.006 

 None 

 None 

 None 



Trace 



169.75 

 47.60 

 6.58 

 1.41 

 o 009 

 0.18 

 None 

 0.093 



Tr. 0.013 

 204.05 



56.74 

 7.66 



1-43 



0.011 



0.20 



Trace 

 0.059 



Trace 



June 8, 1909. 



519-40 



17-50 



160.33 



3-24 

 12.70 

 8.96 

 0.62 

 0.010 



None 



None 



None 



Trace 

 0.017 

 240.90 

 65.87 

 7-34 

 1-59 

 0.01 



None 

 0.0006 

 0068 



Trace 



From the table it is seen that the variation in concentration of the con- 

 stituents during the past year is not as uniform as for the preceding year. 

 Thus, while the concentration of the sodium chloride and of the water as a 

 whole has increased about 18 per cent since 1908, the amount of carbonates 



* Situated at Tucson, Arizona. Grant No. 599. $34,728 for investigations and main- 

 tenance during 1910. (For previous reports see Year Books Nos. 2-8.) 



55 



