586 proceedings: biological society 



the colony, from October to February. The geographical features of 

 British Guiana and the meteorological conditions, especially as to their 

 ecological relations, were described, also the distribution of population, 

 the general conditions of living, and the commercial products. Prof. 

 Hitchcock also described his itinerary, illustrated his remarks with 

 photographs of plants observed and botanical conditions. In answer 

 to questions it was brought out that Prof. Hitchcock's sample of sugar 

 cost ten cents per pound, and that mosquitoes occur everywhere but 

 not so abundantly as in our north. Malaria occurs. 



A. A. DooLiTTLE, Recording Secretary. 



613TH meeting 



The 613th meeting was called to order by Past President Palmer at 

 8.20 p.m., May 15, 1920, in the lecture hall of the Cosmos Club, with 

 47 persons present. The minutes of the preceding meeting were read 

 and approved. 



Under the head of general notes Dr. Palmer referred to the recent 

 meeting of the American Society of Mammalogists and the wealth of 

 material presented in papers on 20 topics. Then followed remarks by 

 Dr. Wetmore on a collection of bones taken by H. E. Anthony from 

 Porto Rican deposits and submitted to him for identification. Several 

 species proved to be new and the collection as a whole tends to fill 

 gaps in the known distribution of birds. 



Regular Program 



Alexander Wetmore: Use of powder down feathers in birds. This 

 paper will appear in full in Condor. 



W. P. Taylor: Habits of the kangaroo rat in Arizona. 



The big kangaroo rat {Dipodomys spectabilis) , the large rounded mounds 

 of which are so conspicuous a feature in many localities in the southwest- 

 em United States, is found to be of considerable economic importance. 

 Its habit of food storage is of particular interest, as it hoards large 

 quantities of the seeds or crowns of several kinds of grama grasses and 

 needle grasses, including some important forage species. Although 

 considerable information on the life history and habits of the animal 

 has been acquired, further investigations are necessary, if a thorough 

 understanding of its relation to its environment is to be gained. Dis- 

 cussed by Messrs. Wetmore, Goldman and Marsh. 



E. A. Goldman: The elk of the Jackson's Hole region in Wyoming. 



Forage conditions were very adverse in Jackson Valley and the win- 

 ter unusually long and severe. There was some starvation of elk at 

 certain outlying points, but the main herd wintered fairly well through 

 feeding carried on by the Biological Survey and the State of Wyoming. 

 An emergency purchase of hay by the Biological Survey undoubtedly 

 saved the lives of thousands of elk. Discussion by Drs. Shufeldt 

 and Marsh. 



E. A. Goldman, Recording Secretary, pro tern. 



