CONTENTS 
ArtuHur, J. C. Problems in the Study of Plant Rusts, 1; 
Berry, E. W. The American Species Referred to Thinnfeldia, 
438. : 
Best, G. N. Revision of the North American Species of Leskea 
(with Plates 15 and 16), 463. 
Bray, W. L. The Tissues of Some of the Plants of the Sotol 
Region (with ten figures), 621. 
Brirron, N. L. Timothy Field Allen (with portrait), 173. 
Brirron, W. E. Vegetation of the North Haven Sand Plains 
(with Plates 23-28), 571. 
Busu, B. F.. A List of the Ferns of Texas, 343. 
Cannon, W. A. Studies in Plant Hybrids : The Spermatogenesis 
of Hybrid Cotton (with Plates 7 and 8), 133. 
—— Studiesin Plant Hybrids: The Spermatogenesis of Hybrid 
Peas (with Plates 17~19), 519. 
CLEMENTS, F. E. Nova Ascomycetum Genera Speciesque, 83. 
CusHMAN, J. A. Desmids from Bronx Park, New York, 513. 
Eastwoop, A. New Species of Oreocarya, 238. 
New Species of Western Plants (with a figure), 483. 
Eaton, A. A.  Isoetes riparia Canadensis and Isoetes Dodgei, 359. 
Evans, A. W. Hepaticae of Puerto Rico — II. Drepanolejeunea 
(with Plates 1-6), 19. 
—— Hepaticae of Puerto Rico—III. Harpalejeunea, Cyrtole- 
jeunea, Euosmolejeunea and Trachylejeunea (with Plates 
20-22), 544. 
Fink, B. Some Common Types of Lichen Formations, 412. 
Gigs, W. J. See Truz, R. H. 
Gorper, K. Regeneration in Plants (with four figures), 197. 
Griccs, R. F. On Some Species of Heliconia (with Plates 29 and 
30 and three figures), 641. 
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