TABLE OF CONTENTS 
V 
The effect upon permeability of polyvalent cations in combination with 
polyvalent anions (with one text figure) Oran L. Raber 382 
The floral anatomy of the Urticales (with Plates XV-XXII). 
Albert Reiff Bechtel 386 
Genetic evidence of aberrant chromosome behavior in maize endo- 
sperm (with one text figure) R. A. Emerson 411 
No. 9, November 
The interrelationship of the number of the two types of vascular 
bundles in the transition zone of the axis of Phaseolus vulgaris (with 
two text figures) 
J. Arthur Harris, Edmund W. Sinnott, John Y. Pennypacker, 
and G. B. Durham 425 
Area of vein-islets in leaves of certain plants as an age determinant 
(with Plate XXIII) M. R. Ensign 433 
Unusual rusts on Nyssa and Urticastrum (with six text figures) 
E. B. Mains 442 
Miscellaneous studies on -the crown rust of oats (with Plate XXIV) 
G. R. HoERNER 452 
Comparative studies on respiration XVIII. Respiration and antagonism 
in Elodea (with two text figures) C. J. Lyon 458 
The effect upon permeability of (I) the same substance as cation and 
anion, and (II) changing the valency of the same ion (with two 
text figures) Oran L. Raber 464 
No. 10, December 
Pollen and pollen enzymes Julia Bayles Paton 471 
The embryogeny of Cyrtanthus parviflorus Baker (with Plates XXV 
and XXVI) Wm. Randolph Taylor 502 
Studies on plant cancers III. The nature of the soil as a determining 
factor in the health of the beet, Beta vulgaris, and its relation to 
the size and weight of the crown gall produced by inoculation 
with Bacterium tumefaciens (with nine text figures) 
Michael Levine 507 
Index to Volume VIII 526 
(Dates of publication: No. i. Mar. 9; No. 2, Mar. 19; No. 3, Apr. 3; 
No. 4, Apr. 30; No. 5, May 24: No. 6, June 30; No. 7, Aug. 31; No. 8, 
Nov. 14; No. 9, Dec. 19; No. 10, Feb. 15, (1922.) 
