Ckyptogamic Botany and Plant Pathology. 



415 



times occasions quite serious injury to tlie celery crop, in some 

 castas materially lessening the product and also rendering the 

 diseased plants less desirable for mai'ket. 



llalstead of the New Jersey Experiment Station sihows that the 

 disease can be held in check by the use of the standard carbonate 

 of copper and ammonia mixture ajpplied with a knapsack 

 sprayer.§ 



The object of this note is chieiiy to call attention to some con- 

 fusion which exists concerning certain morphological chai-iicters 

 of the fungus. Lilce all Gei-cosix)rae the \('getive threads of tlie 

 fungus usually grow largely in the interior of the leaf and when 

 the mitnment at the affected six)t is nearly exhausted, cliistcis of 

 fruiting threads arise from the vegetive ones, and issuing from a 

 stoma of the leaf bear elongated siKirc^ at theii' ends. Two clus- 



* Twelfth Annual Report, N. J, Agr. Expt. Station, 1891. 



