EXPERIMENT STATION BULLETINS. 573 



FOREWORD. 



This bulletin is one of a series bearing upon the diseases of celery. A re- 

 port on the Septoria Leaf Spot has already been issued as Special Bulletin 

 77. The present bulletin discusses a disease which, in general, is less serious 

 than Septoria Leaf Spot, but which frequently causes serious losses. Pub- 

 lications on at least two other celery diseases are contemplated in the near 

 future. The work reported in this article is a result of investigations ex- 

 tending over a period of several years by C. W. Bennett, who for part of this 

 period was a graduate student at Michigan Agricultural College, and later 

 an instructor in the Department of Botany. The work was suggested by 

 Dr. G. H. Coons, and has been carried out under his direction. 



E. A. BESSEY. 



Published April, 1922. 



