388 INDEX TO AMERICAN BOTANICAL LITERATURE 
Graham, M. Centrosomes during early fertilization stages in Preissia 
quadrata. Mem. Torrey Club 17: 323-325. pl. 8. 10.Je 1918. 
Gruber, C. L. Experiences with a fern garden—IJ. Am. Fern Jour. 
7: 114-121. Dirg17:-—III. Am. Fern Jour. 8: 12-16. Mr 1918. 
Haasis, F. W. Comparative length of growing season of ring-porous 
and diffuse-porous woods. Plant World 20: 354-356. N 1917. 
Harper, R. A. The evolution of cell types and contact and pressure 
responses in Pediastrum. Mem. Torrey Club 17: 210-240. f. I-27. 
10 Je 1918. 
Harper, R. M. The vegetation of the Hempstead Plains. Mem. 
Torrey Club 17: 262-286. pl. 7 + f. 1-3. 10 Je 1918. 
Harris, J. A. On the osmotic concentration of the tissue fluids of 
desert Loranthaceae. Mem. Torrey Club 17: 307-315. 10 Je 
1918. 
Harris, J. A., Gortner, R. A., & Lawrence, J. V. Studies on the phy- 
sico-chemical properties of vegetable saps. Biochem. Bull. 4: 
52-78. Mr 1915. 
Hauman-Merck, L. Observations d’éthologie florale sur quelques 
espéces chiliennes. Rev. Chilena Hist. Nat. 17: 153-159. f. 17, 18. 
Je 1913. 
Hazen, T. E. The trimorphism and insect visitors of Pontederia. 
Mem. Torrey Club 17: 459-484. pl. 14, 15 +f. 1-12. 10 Je 1918. 
Hedrick, U. P. Effects of superheated soils on plants. Proc. Soc. 
Hort. Sci. 1905: 51-55. Mr 1908. 
Hicken, C. M. Sobre las Polipodiaceas Argentinas. Rev. Chilena 
Hist. Nat. 14: 123-134. Ig10. 
Hochreutiner, B. P. G. Critical notes on new or little known species 
in the herbarium of the New York Botanical Garden. Bull. N. Y. 
Bot. Gard. 6: 262-299. 27 S 1910. 
Nineteen new species in various genera are described. 
Holden, R. On the anatomy of two Palaeozoic stems from India. 
Ann. Bot. 31: 315-326. pl. 17-20. O 1917. 
Includes Dadoxylon indicum and D. bengalense, spp. nov. 
Hollick, A. Torrey Botanical Club reminiscences. Mem. Torrey 
Club 17: 29, 30. 10 Je 1918. 
Horst, A. Observaciones sobre la biologia de la Tetilla hydrocotylifolia 
DC. Rev. Chilena Hist. Nat. 19: 22-29. pl. 4-6. Ap 10915. 
Léveillé, H. Les Rubus de l’Argentine et du Chili. Rev. Chilena 
Hist. Nat. 24: 90-93. 30 Je 1917. 
