(453 ) 



apparatus which promises to be useful in several branches of 

 scientific observation. Some attention has been given to 

 securing accurate data of the range of temperatures in the 

 larger glass houses of the main conservatories. 



The photographic equipment has been increased and a 

 number of negatives added to the files showing important 

 natural features of the Garden, plants under cultivation, and 

 the progress made in the various construction operations which 

 have been carried on during the year. Outfits have been 

 furnished the various exploring parties sent out by the Garden 

 and the photographs secured add much to the value of the 

 results of this important branch of the activity of the institu- 

 tion. Lantern-slides have been made from such negatives as 

 were found to offer suitable illustrations for the course of lec- 

 tures given in the spring and autumn. 



I made a tour of six weeks through the desert regions of 

 Arizona, Sonora and Texas, during February and March, 

 for the purpose of securing specimens of the larger cacti and 

 other desert plants for the conservatories, and to make some 

 observations on general vegetative conditions in these regions. 

 Several tons of material were secured, embracing, among other 

 notable specimens, a few tree cacti weighing half a ton each. 



Editorial duties in connection with the Bulletin of the Tor- 

 rey Botanical Club and the Botanischcs Ccnlralblatt have 

 been discharged. A number of lectures have been given in 

 various colleges and laboratories. The duties of General 

 Secretary of the American Association for the Advancement 

 of Science were performed at the Pittsburg meeting of that 

 organization, also the duties of Secretary of the Botanical 

 Society of America. During the absence of Dr. N. L. Brit- 

 ton in England, August 16 to September 13, and at other 

 times for short intervals, the work of the Director-in-Chief 

 was performed by me. 



An elementary text-book of plant physiology designed for 

 use in schools and colleges, and containing xii -f- 138 pages 

 with 108 figures, was completed in February and published 

 shortly afterward by Longmans, Green and Company. 



