TABLE OF CONTENTS, VOLUME IV, 1917 
No. I, January 
PAGE 
The influence of certain climatic factors on the development of 
Endothia parasitica (Murr.) And. (with three text figures) 
Neil E. Stevens i 
Gunnera petaloidea Gaud., a remarkable plant of the Hawaiian 
Islands Vaughan MacCaughey 33 
An interesting modification in Xanthium (with three text figures) 
Charles A. Shull 40 
Endophyllum-like rusts of Porto Rico (with plates I-III) 
E. W. Olive and H. H. Whetzel 44 
No. 2, February 
Fifteen- and sixteen-chromosome Oenothera mutants (with nine 
text figures) Anne M. Lutz 53 
The influence of temperature on the growth of Endothia parasitica 
(with one text figure) Neil E. Stevens 112 
No. 3, March 
Matroclinic inheritance in mutation crosses of Oenothera Reyn- 
oldsii (with four text figures) 
Carl D. La Rue and H. H. Bartlett 119 
Duration of leaves in evergreens (with thirteen text figures) 
ViNNiE A. Pease 145 
The relation between evaporation and plant succession in a given 
area (with nine text figures) Frank C. Gates 161 
No. 4, April 
The relation of some rusts to the physiology of their hosts (with 
plates IV and V) E. B. Mains 179 
The development of some species of Agarics (with plates VI-XI) 
A. W. Blizzard 221 
