INDEX TO AMERICAN BOTANICAL LITERATURE 105 
Osterhout, W. J. V. A method of measuring the electrical conductivity 
of living tissues. Jour. Biol. Chem. 36: 557-568. f.r-6. D 1918. 
Osterhout, W. J. V. Note on the effect of diffusion upon the conduc- 
tivity of living tissue. Jour. Biol. Chem. 36: 489, 490. D 1918. 
Parks, H. E. Notes on California fungi. Mycologia 11: 10-21. 
Ja 1919. 
Pennell, F. W. The flower of Agalinis—a correction. Rhodora 20: 
199, 200. 17 D rgr8. 
Pennell, F. W. Notes on plants of the southern United States—IV. 
Bull. Torrey Club 45: 477-482. 23 D 1918. 
Pérez, B. Contribucién al estudio de la Caesalpinia melanocarpa 
Griseb. Univ. Tucuman Dept. Invest. Indust. 6: 17-24. f. I, 2 
1918. 
Rhoads, A. S. Daldinia vernicosa—a pyroxylophilous fungus. My- 
cologia 10: 277-284. pl. 14 +f. 1. 23 N 1918. 
Rixford, G. P. Smyrna fig culture. U.S. Dept. Agr. Bull. 732: 1-43. 
- i-22.: 14 N-I1O3s, 
Contains considerable information of interest to botanists. 
Rosen, H.R. Notes on some methods and terms employed in studying 
the Uredinales. Phytopathology 8: 581-583. N 1918. 
Rosenbaum, J. The origin and spread of tomato fruit rots in transit. 
Phytopathology 8: 572-580. pl. 4 +f.1. N 1918. 
Rusby, H. H. The recognition at sight of poisonous and medicinal 
properties in unknown plants. Jour. Am. Pharm. Assoc. 7: 770- 
784. S 1918.  [Illust.] 
Rydberg, P. A. Rosaceae (conclusion). N. Am. Fl. 22: 481-560. 
30 D1 
Twenty-three new species in Rosa are described. 
Safford, W. E. Cosmos sulphureus, the xochipalli or flower paint ot 
the Aztecs. Jour. Washington Acad. Sci. 8: 613-620. f. I, 2. 
19 N 1918. 
Sargent, C. S. Notes on North American trees.—III. 
Bot. Gaz. 66: 494-511. 18 D 1918. 
Five new species and many new varieties are described. 
Sempers, J. F. Germination of wild cucumber seed. Am. Bot. 24: 
134, 135. N 1918. 
Shamel, A. D. Why navel oranges are seedless. Jour. Heredity 9: 
246-249. f. 1, 2. 13 N 1918. 
Small, J. K. Botanical exploration in Florida in 1917. Jour. N. Y. 
Bot. Gard. 19: 279-290. pl. 219-222. N 1918. 
Titia—lIl. 
