INDEX TO AMERICAN BOTANICAL LITERATURE 369 
Hurd, A. M. Hydrogen-ion concentration and varietal re- 
sistance of wheat to stemrust and other diseases. Jour. 
Agr. Research 23: 373-386. 3 F 1923. 
Johnson, J. A bacterial leafspot of tobacco. Jour. Agr. Re- 
search 23: 481-494. pl. 1-4. 10 F 1923. 
Kidder, N. T. Isle au Haut [Maine] plants. Rhodora 25: 16. 
24 Ja 1923. 
King, C. J. Cotton rootrot in Arizona. Jour. Agr. Research 
£a2 525-$27.. 17.4 2025. 
Larsen, J. A. Association of trees, shrubs, and other vegetation 
in the northern Idaho forests. Ecology 4: 63-67. 21 F 1923 
[Lemay, P.] Flore du Labrador. Nat. Canad. 49: 183-186. 
A list of plants collected in Labrador before 1895. 
Lipman, J. G. Tendencies in agricultural research. Science II 
573 73-76. 19 Ja 1923: 
Lipman, J. G., & Waksman, S.A. The oxidation of selenium by 
a new group of autotrophic micro-organisms. Science II 
57: Go... ¥2 Ja 2923. 
Léhnis, F., & Smith, N. R. Studies upon the life cycles of the 
bacteria—II. Life history of Azotobacter. Jour. Agr. 
Research 23: 401-432. pl. 1-9. 10 F 1923. 
Mackenzie, K. K. Notes on Carex—XII. Bull. Torrey Club 
49: 361-373. 27 Ja 1923. 
Includes 3 new species from eastern North America. 
Manns, T. F., & Adam, J. F. Parasitic fungi internal of seed 
corn. Jour. Agr. Research 23: 495—524. pl. I-13. 17 F 1923. 
McHargue, J.S. Iron and manganese content of certain species 
of seeds. Jour. Agr. Research 23: 395-400. 10 F 1923. 
Mitra, M. Diseases of Zea Mays and Sorghum vulgare caused 
by species of Helminthosporium. Mem. Dept. Agr. India 
19: 219-242. pl. 1-3. F 1923. 
