2 



College ; from diseased white turnips of several varieties taken from 

 the trial grounds of the Experimental Department, and from other 

 parts of the Province, and also from cabbages growing next to the 

 diseased cauliflowers in the garden department 



This organism was also found in large numbers on the plate 

 cultures, sometimes in pure culture, at other times in mixed culture, 

 the most common contaminating organism being the Bacillus fiuores- 

 cens liquefaciens. The rot bacillus was so numerous that a loopful 

 of the rotted or pulpy tissue had to be very largely diluted in order 

 to reduce the numbers on the culture plates to about 60-100 colonies 

 per plate. In all these cases, no fungi were present and no mycelium 

 was ever seen. 



W. Lochhead, Professor of Biology at the College, who also 

 examined some of the cauliflower material, was also unable to find 

 any mycelium of fungi. 



2. Isolation of the organism and study in iJiire cultures. 



The isolation of the causal bacillus was quite easy, as it grew 

 well in ordinary 10 per cent, beef peptone gelatine. The bacillus, 

 whether isolated from diseased cauliflower, turnip or cabbage, or from 

 diflerent plants and varieties of the above plants, showed the same 

 characteristics when grown on various media. Comparative studies 

 of the various germs, isolated from different sources, were made, but 

 no essential morphological or cultural difterences were noticed. 

 Bouillon,* 10 per cent, gelatine, agar, milk, potato, raw and cooked, 

 raw cabbage stems, raw turnip and raw cauliflower were used in this 

 comparative study. 



3. The pure culture of Bacillus oleraceae when introduced into 

 susceptible ijlants produced the characteristic symptorns of the 

 disease. 



A series of inoculation and cross inoculation experiments were 

 made in order to substantiate the relation of the bacillus to the 

 disease. Thus a series of cauliflower, turnip and cabbage plants were 

 inoculated in the following manner : — 



* These terms, when not otherwise stated, refer to media prepared in 

 accordance with the recommendations of the Laboratory Committee of 

 the American Public Health Association. 



