CONTENTS 



1. The Development of Climax Formations in Northern Min- 



nesota. H. F. Bergman and Harvey Stallard - - - ZZZ 



2. The Effects of Certain Rusts upon the Transpiration of 



Their Hosts. /. E. Weaver ------- 379 



3. Response of Micro-Organisms to Copper Sulphate Treat- 



inent. N. L. Huff --------- 407 



4. Studies in the Morphology of Yucca Glauca. Donald Fol- 

 som ------------- 



427 



5. Comments on Malva Rotundifolia L. and Its Allies. H. F . 



Bergman ------------ 437 



6. Observations on Betula in Minnesota with Special Refer- 



ence to Some Natural Hybrids. C. O. Rosendahl - - 443 



7. Reputed Minnesota Plants Which Probably do not Occur 



in the State. C. O. Rosendahl and F. K. Butters - - 461 



