[HARRISON-SADLER] A BACTERIAL SOFT ROT OF TURNIPS 105 



Glycerine, After 72 hours clear in closed arm: no gas: alkaline 

 reaction to litmus. 



Aesculin Agar. Black in 24 hours. 



Neutral Red Glucose Broth. No ring: no gas: no colour change. 



Gelatine Colonies. — 48 hours — rapid growth — colonies not dense, 

 semitransparent : under the § objective, organisms are seen moving 

 en masse: edges of colony ciliate, liquefaction saucer shaped: diam- 

 eter of surface colonies up to 4 mms. 



Potato Gelatine Colonies: 48 hours: growth rapid, round colony, 

 diameter up to 5 mms: outside margin of colony dark zone and de- 

 posits of bacteria in various parts of the colony: edges ciliate. 



In 72 hours the potato gelatine plates are completely liquefied, 

 while the beef gelatine plates have a distinct turnipy smell, the colonies 

 having increased in size to 15 mms. in diameter. 



To the naked eye the colonies appear myceloid, with deposits in 

 the centre. 



In 120 hours the gelatine colonies have a diameter of 25 mms. 

 and in plates where the dilution has been such that not more than one 

 colony is present there docs not seem to be any reason why if given 

 time a single colony will not spread throughout the whole plate. 



Agar Colonies. In 48 hours the colonies on the surface are 1-2 

 mms. in diameter, and the deep colonies punctiform. 



The surface colonies are convex to capitate: glistening with a 

 metallic lustre, with edges entire and gyrose markings in the centres. 



Potato Agar Colonies. In 48 hours the surface colonies are 2-4 

 mms. in diameter: convex to pulvinate; round, glistening and with 

 edges entire. 



The growth is much more massive than on beef agar. 



The optimum temperature for growth is 30°C. 



Experiments relative to the length of time which the organism 

 will exist on specific media have been conducted, but further work 

 will be done. 



For the present it is sufficient to say that beef peptone gelatine 

 and potato gelatine are more suitable for long continued growth than 

 are beef peptone agar and potato agar. 



Inoculations have been made from 14 weeks old gelatine and agar 

 cultures respectively into beef peptone broth, and incubated at 30°C. 

 After 6 days heavy growth the formation of a ring is obtained in 

 the broth inoculated from the gelatine culture, while the broth in- 

 oculated from the agar culture shows very slight cloudiness and growth. 



As is to be expected, much more luxuriant growth and a far greater 

 virulence is noticed when a culture of the organism is used which has 

 been passed through a number of growing plants. 



