TABLE OF CONTENTS 
V 
No. 7, July 
The structure of the chromosomes in Tradescantia virginica L. (with 
eleven text figures and Plates XXIX and XXX).. Harold C. Sands 343 
The effect of ringing a stem on the upward transfer of nitrogen and ash 
constituents (with one text figure).. Otis F. Curtis 361 
The influence of plants on the air in houses 
George B. Rigg, Thomas G. Thompson, and William L. Gilliland 383 
The potentialities of a cell... Charles E. Allen 387 
No. 8, October 
The effect of heat upon the mycelium of certain structural-timber- 
destroying fungi within wood (with one text figure) 
Walter H. Snell 399 
An isoelectric point for plant tissue and its significance (with six text 
figures).... . William J. Robbins 412 
Studies of Lythrum Salicaria I. The efficiency of self-pollination 
A. B. Stout 440 
Chromosome behavior in Acer platanoides L. (with Plates XXXI and 
XXXII). Chester Arthur Darling 450 
No. 9, November 
The physiology of incompatibilities.A. B. Stout 459 
Pollen- and seed-sterility in hybrids. Bradley Moore Davis 462 
Genetical aspects of self- and cross-sterility. E. M. East 468 
Sterility in relation to horticulture.M. J. Dorsey 474 
Genera of North American Fabaceae I. Tribe Galegeae (with Plates 
XXXIII-XXXV).P. A. Rydberg 485 
The cambium and its derivative tissues IV. The increase in growth of 
the cambium (with three text figures and Plate XXXVI) 
I. W. Bailey 499 
Type species of the first 100 genera of Linnaeus’ Species Plantarum 
A. S. Hitchcock 510 
No. 10, December 
Australasian botanical notes III. New Zealand (with six text figures 
and Plate XXXVII). Douglas Houghton Campbell 515 
Hydrogen-ion concentration as related to the Fusarium wilt of tomato 
seedlings (with Plate XXXVIII).... Everett Clifton Sherwood 537 
Studies on the relation of aeration and continuous renewal of nutrient 
solution to the growth of soybeans in artificial culture (with two 
text figures and Plate XXXIX). .. R. V. Allison and J. W. Shive 554 
Index to Volume X. 567 
(Dates of publication: No. 1, Feb. 3; No. 2, Mar. 2; No. 3, Mar. 30; 
No. 4, Apr. 18; No. 5, May 10; No. 6, July 2; No. 7, July 28; No. 8, Oct. 23; 
No. 9, Nov. 27; No. 10, Dec. 31.) ■ 
