VI 



CONTENTS 



[volume lxiii 



PAGE 



The supposed action of potassium permanganate 



with plant peroxidases - H. H. Bunzell and Heinrich Hasselbring 



Leaf nectaries of Gossypium (with plates XII and 



XIII and one figure) ------ E. L. Reed 



The reaction of plant protoplasm - A. R. Haas 



Environmental influences on nectar secretion. 

 Contributions from the Hull Botanical Labora- 

 tory 228 - - Leslie A. Kenoyer 



Development of embryo sac and embryo in 

 Euphorbia Preslii and E. splendens (with 



plates XIV-XVI) ------- Wanda Weniger 



The development of the ascocarp of Rhizina 



undulata Fr. (with plates XVII and XVIII) - Harry M. Fitzpatrick 



Problems of plant pathology ------ F. L. Stevens 



Flowers and insects. XX. Evolution of ento- 

 • mophilous flowers ------- Charles Robertson 



Does the temperature coefficient of permeability 



indicate that it is chemical in nature ? - - W.J. V. Osterhont 



A study in physiographic ecology in Northern 



Florida. Contributions from the Hull Botani- 

 cal Laboratory 229 (with ten figures) - - Laura Gano 



Permeability of certain plant membranes to water. 

 Contributions from the Hull Botanical Labora- 

 tory 230 (with two figures) ----- F. £. Denny 



Arbores fruticesque Chinenses novi. I - Camillo Schneider 



Peculiar effects of barium, strontium, and cerium on 



Spirogyra (with two figures) ----- 5. 5. Chien 



Development of Dumontiafiliformis. II. Develop- 

 ment of sexual plants and general discussion of 

 results (with plates XIX-XXII and seven 

 figures) ---------- Grace A . Dunn 



Permeability of membranes as related to their com- 

 position. Contributions from the Hull Botani- 

 cal Laboratory 231 (with six figures) - - F. E. Denny 



Sexuality of filament of Spirogyra (with plates 



XXIII-XXV) -------- Bert Cunningham 



Orange rusts of Rubus (with one figure) - - - /. C. Arthur 



Arbores fruticesque Chinenses novi. II - Camillo Schneider 



225 



229 

 232 



249 



266 



282 

 297 



307 



317 



337 



373 

 398 



406 



425 



468 



486 



=;oi 



516 







