iv 
TABLE OF CONTENTS 
No. 5, May 
William Gilson Farlow, December 17, 1844-June 3, 191 9 (with Plate 
VIII) 
A. F. Blakeslee, Roland Thaxter, and William Trelease 173 
The development of the thallus of Sphaerocarpos Donnellii Aust. 
(with one text figure and Plates IX-XII) H. W. Rickett 182 
The genus Plantago in Hawaii (with Plate XIII). .Joseph F. Rock 195 
Relation of catalase, oxidase, and H+ concentrations to the formation of 
overgrowths (with two text figures) R. B. Harvey 211 
No. 6, June 
The fusion of the ventral canal cell and egg in Sphagnum subsecundum 
(with Plates XIV and XV) Geo. S. Bryan 223 
The geographical distribution of North Dakota plants (with one text 
figure) O. A. Stevens 231 
Longevity of the seeds of cereals, clovers and timothy (with five text 
figures) H. B. Sifton 243 
On the anatomy of Chenopodium album (with three text figures and 
Plates XVI and XVII) Ernst F. Artschwager 252 
No. 7, July 
Measurement of the catalytic power of catalase (with six text figures) 
L. G. M. Baas Becking and H. C. Hampton 261 
Early stages in the development of certain Pachypsylla galls on Celtis 
(with Plate XVIII) B. W. Wells 275 
The upward translocation of foods in woody plants. II. Is there nor- 
mally an upward 'transfer of storage foods from the roots or trunk 
to the growing shoots? Otis F. Curtis 286 
Early stages in the development of the sporophyte of Sphagnum sub- 
secundum (with 26 text figures) Geo. S. Bryan 296 
No. 8, October 
Byron David Halsted, June 7, 1852-August 28, 1918 (with portrait, 
Plate XIX) F. L. Stevens, L. H. Pammel, and Mel T. Cook 305 
Absorption of moisture by gelatin in a saturated atmosphere (with one 
text figure) Charles A. Shull and S. P. Shull 318 
Slow and rapid growth (with two text figures) H. S. Reed 327 
Cytology and systematic position of Porphyridium cruentum Naegeli 
(with Plates XX and XXI) . . Ivey F. Lewis and Conway Zirkle 333 
Somatic chromosomes in Tradescantia (with Plates XXII and XXIII) 
Lester W. Sharp 341 
No. 9, November 
The cambium and its derivative tissues. II. Size variations of cambial 
initials in gymnosperms and angiosperms (with three text figures) 
I. W. Bailey 355 
