DEPARTMENT 01? BOTANICAL RESEARCH. 6/ 



lages and other colloids, as well as upon the condition of the cell-walls. The 

 analysis of this action may be expected to offer explanation of the remaining 

 cases of xeno-parasitism which failed to survive. 



FIELD OPERATIONS. 



A large share of the problems under investigation by the members of the 

 staff and associates require the examination of material in widely separated 

 localities. A camp in charge of Prof. J. G. Brown, of the University of 

 Arizona, was maintained at the plantations in the Santa Catalina IMountains 

 in Arizona at elevations of 6,000 to 8,000 feet during June, July, and August, 

 191 1. This camp served as a base for several members of the staff. 



Early in the year a few series of observations were carried out from the 

 Desert Laboratory in several directions along radii of 15 to 25 miles by 

 motor transportation. The conditions of civil war in [Mexico caused the 

 cancellation of all plans for fieldwork to the southward in Sonora, as well as 

 in the Delta of the Colorado River adjacent to the Salton Basin. 



The Otero Basin of New ^Mexico was reached by rail, and in March a 

 party followed a network of routes across it and the San Francisco Moun- 

 tains. Both teams and motors were employed in this work. The great inte- 

 rior valley of California and an arm of the Mojave Desert were traversed 

 in June ; some travel in accordance with the method of previous years was 

 made by boat and wagon on and around the Salton Lake in late summer. 



The work of Dr. W. A. Cannon in Algeria carried him into regions in 

 which the distributional features of desert vegetation have not hitherto been 

 considered by botanists. Details are to be found in another section. 



EQUIPMENT. 



The structural additions to the facilities of the department include a plas- 

 tered brick addition to the adobe laboratory to be used as an office for the 

 Desert Laboratory, a concrete-lined stone reservoir of a capacity of 6,000 

 gallons for service to the shop, and experimental cultures and several cages 

 and shelters for beetles and plants. Various articles of camping and packing 

 outfit have been purchased. A heavy cart suitable for carrying material up 

 the heavy grade of Tumamoc Hill has been secured. A motorcycle, origi- 

 nally purchased to be used by Dr. W. A. Cannon in the Algerian deserts, 

 has been brought to Tucson and refitted for messenger use from the office. 

 A i2-horsepower runabout which served the office has been used as part pay- 

 ment on a 20-horsepower motor, with which short field trips may be most 

 expeditiously made to places within 20 miles of the laboratories. The larger 

 machine is reserved for more serious expeditions with heavy equipment, and 

 this vehicle has now carried parties one or more times over a region extend- 

 ing from Port Lobos on the Gulf of California in Sonora to San Francisco, 

 over many stretches of country scarcely practicable for loaded wagons. A 

 small tract of garden land has been acquired at Carme! for use in the accli- 



