DEPARTMENT OF BOTANICAL RESEARCH.* 

 D. T. MacDougai,, Director. 



The activities of the members of the staff during the year have been chiefly 

 directed to the reduction of data, the collocation of observations, and the 

 carrying out of special series of experiments for the completion of work 

 upon problems that have been under investigation for some time. The 

 operations of the Department have been extended by the establisliment of the 

 laboratory at Carmel, California, which will be devoted chiefly to acclimatiza- 

 tion experiments. This, together with the alluvial experimental garden at 

 Tucson, makes the equipment very effective for the analysis of the influence of 

 climate on plants, with respect to heredity and evolution. Title to the Tucson 

 garden has been acquired and the garden has been improved. Cooperation 

 of the Department with other institutions and individuals has been gratify- 

 ingly successful, as described in the following pages. Geologists, zoologists, 

 climatologists, and botanical specialists of all kinds are making an increasing 

 use of the facilities of the Desert Laboratory. 



MOVEMENTS OF VEGETATION IN THE SALTON BASIN. 



The level of the Salton Lake had fallen 135 inches in October, 1909, below 

 the maximum of February, 1907. The salt-content of the water, which was 

 333 parts in 100,000 at the maximum, was found to have increased to 520 in 

 samples taken in June, 1909. The older beaches bared during the summer 

 of 1907 are now fast approaching the conditions of soil moisture character- 

 istic of deserts and prevalent before the formation of the lake. In previous 

 reports some notice has been given of the occupation of these beaches by 

 vegetation, and now the tops of some small hills in the basin are being 

 uncovered as islands and offer foothold for plants. The earliest occupants 

 have been seen on a few of these, and the use of these islands as nesting- 

 places by pelicans and penguins has given opportunity for observing their 

 agency in the dissemination of seeds. 



The members of the staff have had the benefit of the advice and counsel of 

 several specialists in connection with this work. Prof. W. P. Blake, terri- 

 torial geologist of Arizona, and the discoverer of the sub-sea-level basin in 

 which the lake lies, has been in frequent consultation. Prof. C. F. Tolman, 

 of the University of Arizona, accompanied an expedition around the lake in 

 November, 1908, and gave some helpful interpretations of certain geological 

 phenomena. Prof. W J McCee, Mr. E. E. Free, and Dr. James M. Bell, of 



* Situated at Tucson, Arizona. Grant No. 537. $32,000 for investigati-^ns and main- 

 tenance. (For previous reports see Year Books Nos. 2, 3, 4, 5, 6, and 7. J 



57 



