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Signs of the Naturally Occurring Disease. 



Early manifestations of the disease are rare. In an advanced stage the leaves 

 wilt, hang down, dry and wither. The rotted material at times breaks through 

 the skin, giving rise to a very distinctive and putrid smell. The natural turnip 

 odour seems to be exaggerated to ofifensiveness. In many cases the root looks 

 sound on the outside, and the crown of leaves is erect and healthy looking, but a 

 smart tap of the foot will cause the collapse of the turnip, and the interior will 

 be found to be composed of a soft, pulpy dark mass. In such cases the leaves 

 evidently obtain their supplies by the last ring, which is not diseased. 



Isolation from naturally infected plants was easily carried out in ordinary 

 media. The rotted portion of infected turnip was crowded with an organism 

 practically in pure culture, and high dilutions were necessary in order to obtain 

 discrete colonies. After isolation from the initial set of plates, the organism was 

 again plated and replated. 



After working out the morphology and cultural characteristics, a series of 

 growing turnip plants was inoculated. These plants were grown under glass. The 

 soil used was from rotted turf and sand. 



Experiments zvith Groiving Plants. 



In the first trial, the crown of a turnip plant was punctured with a sterile 

 needle and then the inoculation was made with material from a young agar 

 culture. 



5.— Turnip Rot organism from B. P. agar at ."JO" C. x 1000 



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