NOTES AND COMMENT 193 



value. Through no other agency will be able to learn so much about 

 the ecology of forest trees and the nature of the conditions in our di- 

 versified forest areas. 



Mr. C. R. Tillotson has recently prepared a pamphlet on Nursery 

 Practice on the National Forests (Department of Agricultme, Bull. 

 No. 479), which contains a very full account of the methods by which 

 seedling trees are produced, cared for, and transplanted in the nurseries 

 of Nebraska, Idaho, Washington, and California. 



The Agricultm-al Experiment Station of Colorado has i.ssued a bul- 

 letin on the Native Vegetation and Climate of Colorado in their Rela- 

 tion to Agi-iculture, prepared by Prof. Wilfred W. Robbins. The avail- 

 able temperatine and precipitation data have been assembled, digested 

 and discussed in their relation to vegetation and crop possibilities. Maps 

 are given showing the distribution of mean summer temperatures, aver- 

 age length of frostless season, average date of last spring frost, and mean 

 annual precipitation. After describing the climatic conditions for the 

 state as a whole the author treats each of the vegetational regions in 

 greater detail. The ten stations in the yellow pine forest region vary in 

 mean annual precipitation from 14.79 inches at the dryest to 24.36 inches 

 at the wettest. The growing season is shown to receive approximately 

 half of this amount. The eleven stations in the sagebrush shrub-steppe 

 vary in precipitation from 7.94 inches to 18.69 inches. Similar illumi- 

 nating comparisons are made between the temperatm*e conditions of these 

 and other areas. In the discussion of climatic details and their relation 

 to agricultural plants the author shows great familiarity with his state 

 and with the problem? under investigation. The large number of 

 workers who will be interested in Professor Robbins' very compact 

 bulletin will have a suspicion that he could have written one five times 

 as thick without exhausting his data or the diversities of his state and 

 its problems. 



An important contribution to West Indian taxonomy has been made 

 by Dr. Otto E. Jennings, who has published a list of the plants collected 

 by himself and others in the Isle of Pines, and now contained in the 

 herbarium of the Carnegie Museum. A very brief description of 

 the vegetation of the island shows two of its important formations to 

 be pine barren and open forest of slash pine, bearing considerable 

 resemblance to the adjacent barrens of the province of Pinar del Rio 

 in Cuba. 



