diseased parts of caulitiower and turnip plants, and were stained by- 

 various methods. The most satisfactory results were obtained by 

 staining over night in carbol fuchsin, washing out the surplus stain 

 first with water, and then with 97 per cent, alcohol, clearing in 

 oil of cloves and mounting in Canada balsam. A number of sections 

 were also stained with anilin blue. The latter method gave fair 

 results; but the former method was the more satisfactor}-. 



Completely rotten caulitiower or turnip was difficult — in fact it 

 was almost impossible — to imbed in paraffin, as the whole mass fell 

 to pieces when thrown into alcohol. Portions of petiole, stem, or 

 flower of cauliflower, where the disease was just starting and pieces 

 of tissue in a more advanced stage from which most of the soft parts 

 had been cut away, furnished the best material for study. 



Cross sections showed the bacteria in the intercellular spaces^ 

 where they increased rapidly and as soon as sufficient enzyme was 

 elaborated, it softened the middle lamella and permitted the bacteria 

 to penetrate between the cells. These enzymes had a marked action 

 on the cell-wall, which gradually swelled up and lost all trace of its 

 striated character. The cell wall at this stage also lost veiy largely 

 its faculty of taking up the stain, and sections stained with carbol 

 fuchsin showed the enormously thickened cell- wall, faintly stained a 

 pale pink, while adjacent healthy cell-walls were deep red in color 

 and showed very plamly the middle lamella and striations. 



The figures 9-10 show the difterent stages in the destruction of 

 the cells by this bacillus. Fig. 9 shows the bacteria in some numbers 

 in the intercellular spaces, some are just beginning to penetrate along 

 the middle lamella At this period, the cell-wall is stained deeply. The 

 last stage, just before the absolute collapse of the tissues, may be seen 

 in Fig. 10, in which the lumen of the cells is very small due to the 

 enlarging and softening of the cell- walls which now stain even 

 more faintly than before. The bacteria have also enormously 

 increased. 



Sections of pieces of turnips aflfected with the rot, showed^ 

 slightly diftVrent features ; although the action of the bacillus was 

 the same. 



Turnips cells have much thinner walls than the cauliflower 

 petiole, or stem ; consequently, when attacked with rot they collapse 



