DEPARTMENT OF BOTANICAL RESEARCH. JI 



Sykes, and Dr. D. T. IMacDougal, of the Desert Laboratory, was organized 

 to make a survey of the region in question. A field outfit was drawn from 

 the equipment of the Desert Laboratory, and Messrs. Hornaday and PhilHps 

 contributed a sum in cash equal to half of the field expenses, which were not 

 inconsiderable. The route traversed followed due west from Tucson for more 

 than a hundred miles, then due south across the International boundary at 

 Monument 167. By the intervention of President Roosevelt and Hon. Elihu 

 Root, the expedition was given clearance on its material by the ]Mexican gov- 

 ernment and a detail of the fiscal guard marched over a hundred miles to re- 

 ceive and safeguard the entrance of the party. The known routes of travel 

 were left at Monument 180 west of Sonoyta, and from thence the party in 

 various detachments went due south around the Pinacate group of volcanoes 

 and to the shores of Adair Bay. 



The height of the Cobabi Peak, near Sonoyta, was reduced from 9,425 

 feet, as given on maps of the U. S. Hydrographic Survey, to 4,325 feet, and 

 the position of the principal topographic features were plotted by Mr. Sykes. 



The Pinacate Mountains were found to include an oval mass of volcanic 

 cones and lava beds about 40 miles in length and parallel to the axis of the 

 Gulf near Adair Bay. The culminating peak was climbed for the first time 

 and its elevation fixed at 4,300 feet by carefully corrected aneroids. Over 

 200 volcanic cones are visible from its summit, many of which had fairly per- 

 fect craters. In addition, many sunken craters were found, some of which 

 were of great depth and size. One, designated as Sykes Crater, has a depth 

 of 750 feet and a diameter of 2,000 feet. The floors of these craters bore an 

 abundant vegetation. Among other important facts the Canada mountain- 

 sheep (Ovis canadensis) was found here in great abundance, sometimes liv- 

 ing in these deep craters, but little above the sea-level in altitude. 



It was found also that some of the plants of the Tucson region, including 

 the sahuaro (Cereus gigantens), creosote-bush {Covillea tridentata), Bncelia 

 farinosa, cholla (Opuntia fulgida), and a few others, actually descend to 

 nearly sea-level, thus showing a vertical range of 4,000 feet and covering sev- 

 eral degrees of latitude. The botanical facts obtained will not only be valu- 

 able when correlated with the results of detailed surveys being made in the 

 Tucson region, but will also have a direct bearing upon some phases of the 

 acclimatization experiments. 



The contact of desert and littoral in this region brings about some highly 

 interesting topographical and biological features. A great ridge of dunes a 

 few miles in width and in places 80 to 100 feet in height has been formed 6 to 

 8 miles from the shore and roughly parallel to it. Between this and the salt 

 water runs a great level stretch of tall galleta grass and halophytes. The 

 dunes themselves bear a strictly desert vegetation. The streamways from the 



