INDEX TO AMERICAN BOTANICAL LITERATURE 47 
McLean, F. T. A study of the structure of the stomata of two species 
of Citrus in relation to citrus canker. Bull. Torrey Club 48: 101- 
106. f. r. 4 Ap 1921. 
McLean, F. T., & Lee, H. A. The resistance to citrus canker of Citrus 
nobilis and a suggestion as to the production Of resistant varieties in 
other Citrus species. Phytopathology 11: 109-114. f. z. Mr 1921. 
McNair, J.B. <A study of Rhus diversiloba with special reference to its 
toxicity. Am. Jour. Bot. 8: 127-146. pl. 2+/f.1, 2. 3 Ap 1921. 
McNair, J. B. The morphology and anatomy of Rhus diversiloba. 
Am. Jour. Bot. 8: 179-191. pl. 3, 4. 30 Ap 1921. 
McNair, J. B. The transmission of Rhus poison from plant to person. 
Am. Jour. Bot. 8: 238-250. 24 My 1921. 
Menaul, P. Note on the formation of hydrocyanic acid in plants. 
Jour. Biol. Chem. 46: 297. Ap 1921. 
Merriman, M. L. The receptacle of Achillea Millefolium L. Torreya 
21: 21-24. f. 5: “Ap 192i. 
Morse, W. J. The transference at potato late — ig insects. 
Phytopathology 11: 94-96. F 1921. 
Mousley, H. Further notes on the orchids of Hatley, Stanstead Co., 
Quebec, 1920. Canad. Field Nat. 34: 169-173. 12 My-1g21. 
Muttkowski, R. A. Copper in animals and plants. Science II. 53: 
453, 454. 13 My tgat. 
Needham, J. G. A biological examination of Lake George, N. Y. 
Sci. Mo. 12: 434-438. My 1921. 
Nelson, J. C. Additions to the flora of western Oregon during 1920. 
Torreya 21: 24-28. p 1921. 
Oakley, R. A., & Evans, M. W. Rooting stems in timothy. Jour. 
Agr. Research 21: 173-178. pl. 39, 40. 2 My 1921 
Orton, C. R. Lightning injury to potato and cabbage. Phytopathol- 
ogy 11: 96-98. f. z. F 1921. 
Palmer, E. J. Botanical reconnaissance of southern Illinois. Jour. 
Arnold Arbor. 2: 129-153. Ja 1921. 
Peattie, D. C. An interesting habitat. Rhodora 23: 69-71. 20 Ap 
Pennell, F. W.  ‘‘Veronica’” in North and South America. Rhodora 
23: I-22, 29-41. _ 1921. 
Includes Veronica catenata sp. nov., and several new combinations. 
Pieters, A. J., & Kephart, L.W. Annual white sweet clover and strains 
of the biennial form. U.S. Dept. Agr. Dept. Circ. 167: I-21. f. 
6. Ap eoat. 
