INDEX TO AMERICAN BOTANICAL LITERATURE 131 
Thom, C. C., & Holtz, H. F.. Factors influencing the water require- 
ments of plants. Washington Agr. Exp. Sta. Soil Physics Bull. 
146: 1-64. f. 1-18. Je 1917. 
Tisdale, W. H. Relation of temperature to the growth and infecting 
power of Fusarium Lini. Phytopathology 7: 356-360. pl. rz + 
Fs lad O 1017: 
Traver, J. The American larch or tamarck, a tree of the swamps. 
Nature Study Rev. 13: 341-345. N 1917. [Illust.] 
Trotter, A. Osservazionie ricerche istologiche sopra alcune morfosi 
vegetali determinate da funghi. Marcellia 15: 58-111. pl. 1-3 + 
f. toe 41 Au sot. 
Trumbull, H. L., & Hotson, J. W. The effect of Roentgen and ultra- 
violet rays upon fungi. Phytopathology 7: 426-431. f. 1, 2. 
3 2) 1677. 
Van Eseltine, G. P. Selaginella fusiformis, a new species in the S. 
rupestris group. Proc. Biol. Soc. Washington 30: 161, 162. 10 O 
1917. 
Vestal, A.G. Foothills vegetation in the Colorado front range. Bot. 
Gaz. 64: 353-385. f. 1-8. 16 N 1917. 
Victorin, M. Découverte du lycopode petit-cypres dans les Lauren- 
tides. Le Naturaliste Canadien 39: 166-170. My 1913. 
Victorin, M. Notes botaniques. Le Naturaliste Canadien 40: 78, 79. 
N 1913. 
Victorin, M. Notes sur deux cas d’hybridisme natural. Le Natur- 
aliste Canadien 39: 177-189. f. 1-4. Je 1913. 
Victorin, M. Plusieurs ‘‘Cyperacies”’ nouvelles pour la flore de Québec. 
Le Naturaliste Canadien 39: 117-123. f.1, 2. F 1913. 
Waterman, W. G. Plant ecology and its relation to agriculture. 
Science II. 46: 224-228. 7S 1917. 
Weatherby, C. A. Color forms of Impatiens biflora. Rhodora 19: 
195-418... 2 JL 1917. 
Weatherby, C. A. Concerning Polystichum acrostichoides forma lan- 
ceolatum. Am. Fern Jour. 7:90, 91. 2 Jl 1917. 
Weatherwax, P. The development of -the spikelets of Zea Mays. 
Bull. Torrey Club 44: 483-496. pl. 23 +f. I-33. 10 1917. 
Weimer, J. L. Three cedar rust fungi, their life histories and the 
diseases they produce. Cornell Agr. Exp. Sta. Bull. 390: 507-549. 
jf. 130-157. My 1917. 
Weir, J. R. A needle blight of Douglas fir. Jour. Agr. Research 1o: 
99-103. pl. 12 +f. 1-3. 9 Jl 1917. 
