BOTANY. 



723 



grown on lime soils, is without effect, while the proper application of 

 combined nitrogen in suitable fertilizers will prove advantageous in 

 increasing plant growth. In general a small quantity of nitrogenous 

 fertilizer may be profitably added to soils where root tubercle bacteria 

 are present in considerable quantity. 



On the assimilability of organic nitrogen in sterilized media, 

 A. Lyebyedyev [Selsle. Khoz. i Lyesov., 186 (1897), No. 7, pp. 159-169).— 

 Sand cultures were conducted with barley in which 2 seeds were planted 

 in each of 11 vessels, the sand having been previously sterilized by igni- 

 tion and washed with hydrochloric acid. The sources of nitrogen sup- 

 plied were urea, hippuric acid, leucin, aspartic acid, and asparagin. 

 Carbonate of lime was added so as to render the different cultures as 

 nearly neutral as possible. Part of the vessels were sterilized; the 

 others not. To the lots which were not sterilized a few drops of aque- 

 ous soil extract were added. All the seeds, whether in sterilized or 

 nou sterilized vessels, were placed for one minute in a 5 per cent solu- 

 tion of corrosive sublimate before planting. During the experiment, 

 which lasted from July to September, particular pains were taken that 

 the water which was given the plants should in no way convey bacteria 

 to the cultures. The results obtained are shown in the following table: 



Assimilation of organic nitrogen by barley. 



a Vessel holding culture broken. 



b No duplicate of this lot in sterilized sand. 



From the above table it is shown that under the conditions of this 

 experiment the seeds germinated in sterilized media, but with the 

 exception of those which had received asparagin were unable to develop 

 their plants to any considerable extent. The experiment, however, 

 corroborates the claim that in sterilized media plants can obtain some 

 nutrition from organic compounds containing nitrogen. — p. fireman. 



The geographical distribution of cereals in North America, 

 O. S. Plumb ( U. 8. Dept. Agr., Division of Biological Survey Bui. 11, pp. 

 24, map l,jigs. 3). — The author has sought to give the distribution of 

 varieties of corn, wheat, and oats adapted to the different life zones as 

 elaborated by Dr. Merriam of this Department. The information upon 

 which this work is based was secured by sending blanks to about 2,500 

 grain growers throughout the United States and Canada. From the 



