352 INDEX TO AMERICAN BOTANICAL LITERATURE 
Sherbakoff,C.D. Tomatodiseases. Florida Agr. Exp. Sta. Bull. 146: 
119-132. f. 32-44. Mr 1918. 
Shive, J. W., & Martin, W. H. A comparison of salt requirements for 
young and for mature buckwheat plants in water cultures and sand 
cultures. Am. Jour. Bot. 5: 186-191. 16 My 10918. 
Shufeldt, R.W. The much-despised skunk cabbage—earliest of spring 
flowers. Am. Forestry 24: 225-231. f. 3-12. Ap 1918. 
Silveira, A. A. da. Contribuicio para as Eriocaulaceas brasileiras. 
Arch. Jard. Bot. Rio de Janeiro 2: 7, 8. pl. 1, 2. 1918. 
Includes descriptions of Paepalanthus densifolius and P. capanemae, spp. nov.- 
Sinnott, E.W. Evidence from insular floras as to the method of evolu- 
tion. Am. Nat. 52: 269-272. F 1918. 
Small, J. K. Ferns of tropical Florida. i-ix + 1-80. pl. 1-5. New 
York. 1918.  [Illust.] 
Pycnodoria pinetorum sp. nov. is described. 
Smith, G. M. The vertical distribution of Volvox in the Plankton of 
Lake Monona. Am. Jour. Bot. 5: 178-185. 16 My 10918. 
Stevens, F. L., & Anderson, H.W. Protect the wheat crop. Eradicate 
the common barberry from Illinois. Illinois Agr. Exp. Sta. Ext. 
Cire. 22: 1~4. f. 1-3. Ap 1918. 
Stewart, F. C. The velvet-stemmed Collybia—a wild winter mush- 
room. N. Y. Agr. Exp. Sta. Bull. 448: 79-98. pl. 1-10. F 1918. 
{Illust.] 
Stevenson, J. A. The green muscardine fungus in Porto Rico. Jour. 
Dept. Agr. Porto Rico 2: 19-32. pl. r. Ja 1918. 
Sumstine, D. R. Fungi of Chautauqua County, N. Y. N. Y. State 
Mus. Bull. 197: 111-118. 1 My 1918. 
Truog, E. Soil acidity—I. Its relation to the growth of plants. Soil 
Sci. 5: 169-195. Mr 1918. 
Turner, W. F. Nezara viridula and kernel spot of pecan. Science II. 
47: 490, 491. 17 My 1918. 
Vinall, H. N., & Reed, H.R. Effect of temperature and other meteoro- 
logical factors on the growth of sorghums. Jour. Agr. Research 13: 
133-148. pl. 12, 12. 8 Ap 1918. 
Vries, H.de. Mass mutations and twin hybrids of Oenothera grandiflora 
Ait. Bot. Gaz. 65: 377-422. f. 1-6. 15 My 1918. 
Vries, H. de. Mass mutation in Zea Mays. Science II. 47: 465-467. 
10 My 1918. 
Weir, J. R. Effects of mistletoe on young conifers. Jour. Agr. Re- 
search 12: 715-718. pl. 37. 18 Mr 1918. 
