MCCULLOCH'S CAULIFLOWER SPOT: SIGNS 313 



where does the organism summer over? Can you obtain the 

 disease on the bleached flowering parts? 



Histology. Fix in Carney's solution pieces of cauliflower 

 leaves and heads showing small spots, carry them through the 

 paraffin-infiltration process, section on the microtome, stain and 

 study. What are your conclusions regarding manner of infec- 



> 

 I 



t 



/ 



, V 



FIG. 237. Flagella of Bacterium maculicolum. Stained from a 2- day agar streak 

 by van Ermengem's method. X 1000. 



tion and process of tissue destruction? Is the disease ever 

 vascular? Is cellulose destroyed? 



Variability. Nothing is known. 



Transmission. Nothing is known, 







LITERATURE 



Read McCulloch: "A Spot Disease of Cauliflower." Bul- 

 letin 225, Bureau of Plant Industry. Washington, D. C., 

 Government Printing Office, 1911. The organism is described 

 and named in this paper. 



