iv 
TABLE OF CONTENTS 
The effect of the endrot fungus on cranberries (with three text figures) 
Neil E. Stevens and Fred W. Morse 235 
Endothia pigments. II. Endothine red (with three text figures) 
Chas. E. Sando 242 
Growth and variabihty in HeHanthus (with three text figures) 
H. S. Reed 252 
No. 7, July 
The structure of protoplasm R. A. Harper 273 
George Francis Atkinson (with portrait, Plate XXXV) 
W. G. Farlow, Roland Thaxter, and L. H. Bailey 301 
Publications of George Francis Atkinson .. Harry M. Fitzpatrick 303 
Viability of detached root-cap cells L. Knudson 309 
No. 8, October 
Venation and senescence of polyembryonic Citrus plants (with six 
text figures) M. R. Ensign 311 
A study of some factors in the chemical stimulation of the growth of 
Aspergillus niger (with two text figures) 
Robert Aaron Steinberg 330 
No. 9, November 
A study of some factors in the chemical stimulation of the growth of 
Aspergillus niger (concluded) Robert Aaron Steinberg 357 
An index of hardiness in peach buds (with two text figures) 
Earl S. Johnston 373 
Notes on the dasheen and chayote (with five text figures) 
Heber W. Youngken 380 
The development of the gametophyte and the distribution of sexual 
characters in Funaria hygrometrica (L.) Schreb. (with Plate XXXVI) 
Mabel Mary Brown 387 
No. 10, December 
Influence of sugars on the growth of albino plants 
L. Knudson and E. W. Lindstrom 401 
Variations in Pleurage curvicoUa (Wint.) Kuntze. . . .J. L. Weimer 406 
Inheritance of sex in Mercurialis annua (with plates XXXVI I-XL 
and one text figure) Cecil Yampolsky 410 
Germination and further development of the embryo of Zea Mays 
separated from the endosperm (with plate XLI) 
Demetrius Ion Andronescu 443 
Index to Volume VI 453 
(Dates of publication : No. i , Feb. 3 ; No. 2, Mar. i ; No. 3, Apr. 28 ; No. 4, 
May i; No. 5, June 20; No. 6, July 21; No. 7, Aug. 16; No. 8, Nov. 22; 
No. 9, Dec. 18; No. 10, Jan. 7.) 
