INDEX TO AMERICAN BOTANICAL LITERATURE 99 
Clute, W. N. The toad lily, Tricyrtis hirta. Am. Bot. 26: 138-140. 
N 1920. 
Coulter, M. C. Origin of mechanism of heredity. Bot. Gaz. 70: 
459-464. 30 D 1920. 
Coville, F.V. The influence of cold in stimulating the growth of plants. 
Jour. Agr. Research 20: 151-160. pl. 20-35. 15 O 1920. 
Cummings, M. B., & Jones, C. H. The aerial fertilization of plants 
with carbon dioxid. Vermont Agr. Exp. Sta. Bull. 211: 1-56. 
pl. 1-8. My 1918. = 
Dachnowski, A. P. Correlation work in peat-land problems. Bot. 
Gaz. 70: 453-458. 30 D 1920. 
Davis, B. M. The problem of the introductory course in botany. 
Science IT. 52: 597-599. 24 D 1920. 
Dickson, B. T. Sclerotinia wilt of greenhouse tomatoes. Phytopath- 
ology. 10: 500, 501. f. 2. 1920. 
Dickson, B. T. Stem-end rot of greenhouse tomatoes. Phytopath- 
ology 10: 498-500. f. Ir. 1920. 
Dixon, H. N. Contributions to Antarctic bryology. Bryologist 23: 
65-71. pl. 4. 2 D 1920. 
Includes 3 new species. 
Ducke, A. Pajura e oity-coré. Arch. Mus. Nac. Rio Janeiro 22: 
63-68. 1919.  [Illust.] 
. Includes Couepia rufa and Lucuma speciosa, spp. nov. 
Durrell, L. W. A preliminary study of the purple leaf sheath spot of 
corn. Phytopathology 10: 487-495. f. 1-6. 23 N 1920. 
Edwards, J. G. Flower and seed of Hedyosmum nutans. Bot. Gaz. 
70: 409-424. pl. 34-36. 30 D 1920. 
Fernald, M. L. Rubus recurvicaulis Blanchard, var. armatus, n. var. 
Rhodora 22: 168. 7 D 1920. 
Folsom, D. Potato mosaic. Maine Agr. Exp. Sta. Bull. 292: 157-184. 
f. 28-30. Au 1920. 
Forsaith, C.C. Anatomical reduction in some alpine plants. Ecology 
I: 124-135. pl. 3, 4. Ap 1920. 
Free, E. E. Imbibition of gelatine and agar gels in solution of sucrose 
and dextrose. Carnegie Inst. Washington Year Book 16: 66. 1917. 
Friesner, R. C. Daily rhythms of elongation and cell division in 
‘certain roots. Am. Jour. Bot. 7: 380-406. pl. 24, 25. 7 D 1920. 
Gleason, H. A. The botanical gardens of New York. Sci. Am. Mo. 
3: 24-27. Ja 1921. 
