Arthur: Cultures of Uredineae in 191 i 51 



An extended excursion, but too late for the season's cultures, 

 was made by the writer and Dr. Frank D. Kern during August 

 and September to the foothills of Colorado, between Boulder and 

 Pueblo, and to some extent in the adjacent mountains. This is 

 the richest rust flora, both in species and frequency of occurrence, 

 yet encountered. The dryness of the atmosphere, which pro- 

 motes the growth of the rust on the individual hosts, while 

 checking the spread from plant to plant, makes the region an 

 exceptionally fine one for field study of relationships between the 

 alternate stages of heteroecious species. Our work was enor- 

 mously promoted by assistance from Mr. E. Bethel, of Denver, 

 whose exact, enthusiastic, and prolonged observations over the 

 whole region visited cannot be too highly commended. The 

 freedom with which he turned over for our use his most impor- 

 tant discoveries and conclusions must unfortunately be inade- 

 quately repaid. It was due to his assistance that this excursion 

 proved the richest in results by far of any yet undertaken, results 

 that are only slightly reflected in this report, but have paved the 

 way for important cultures in 1912. 



On the eleventh of November, after a day of summer heat, a 

 hurricane did great injury to the conservatory and greenhouse 

 of the Experiment Station, in which many plants for the next 

 season's experiments were growing. At about nine o'clock in 

 the evening a large part of the glass in these houses, and in the 

 offices and laboratories of the department of botany, was broken 

 in by the violence of the wind. The heavy rain which was fall- 

 ing soon turned to snow, and the temperature dropped to many 

 degrees below freezing. When the damage was detected at about 

 eight o'clock the next morning, the plants were largely beyond 

 recovery. 



Hearty thanks are due to the following persons who con- 

 tributed material for study : Mr. E. Bethel, Denver, Colo., head- 

 ing the list with 87 collections; Messrs. E. W. Olive, Brookings, 

 S. D., J. M. Bates, Red Cloud, Neb., J. Dearness, London, Ont., 

 and W. P. Eraser, Pictou, Nova Scotia, each sent between 10 

 and 30 collections, while much smaller numbers were sent by 

 Messrs. E. Bartholomew, Stockton, Kans., C. F. Baker, Clare- 

 mont, CaHf., J. F. Brenckle, Kulm, N. D., J. C. Blumer, Tucson, 



