iv 
TABLE OF CONTENTS 
Notes on the distribution and growth of North Dakota Cuscutae 
(with twelve text figures) O. A. Stevens 185 
Lysichiton camtschatcense (L.) Schott, and its behavior in sphag- 
num bogs (with five text figures) Gote Turesson 189 
No. 5, May 
Significant accuracy in recording genetic data E. M. East 211 
Relation of oxidases and catalase to respiration in plants. 
Charles O. Appleman 223 
Influence of certain salts and nutrient solutions on the secretion 
of diastase by Penicillium Camembertii (with three text 
figures) William J. Robbins 234 
No. 6, June 
The archegonium and sporophyte of Treubia insignis Goebel 
(with six text figures) .... Douglas Houghton Campbell 261 
The orientation of primary terrestrial roots with particular re- 
ference to the medium in which they are grown (with 
seven text figures.) Richard M. Holman 274 
A study of development in the genus Cortinarius (with one text 
figure and plates VIII-XIII) Gertrude E. Douglas 319 
No. 7, July 
The development of the Phylloxera vastatrix leaf gall (with five 
text figures and Plates XIV and XV). .Harry R. Rosen 337 
Correlations between morphological characters and the saccharine 
content of sugar beets (with eight text figures). 
Frederick J. Pritchard 361 
Mutation in Mattiola annua, a Mendelizing species (with three 
text figures) ; Howard B. Frost 384 
The growth of forest tree roots W. B. McDougall 384 
No. 8, October 
The angular micrometer and its Uvse in delicate and accurate mi- 
croscopic measurements (with four text figures). 
Howard E. Pulling 393 
Influence of the medium upon the orientation of secondary ter- 
restrial roots (with three text figures) . Richard M. Holman 407 
The anatomy and phylogenetic position of the Betulaceae (with 
plates XVI-XIX) Carl S. Hoar 415 
