JOXES SOFT ROT OF CARROT, ETC. I CAUSE 



231 



potato juice in fermentation tubes, ^ the gas being 20 per 

 cent CO2 and 80 per cent explosive), heat-sensitive (thermal 

 death-point 51°C. — even 10 minutes in bouillon at 47°C, re- 

 tards growth), dry-air-sensitive (sometimes even to 2 minutes' 

 exposure — Jones), sunlight-sensitive (10 minutes of direct sun- 

 light and 2 hours of diffused sunlight, fatal — Jones), not ex- 

 ceedingly frost-sensitive (frozen in +15 peptone beef bouillon, 

 in 1919, 13 per cent survived) short, rod-shaped, catenulate, 

 or filamentous (up to 200^ or more — Jones) schizomycete 



Fig. 172. — Cross-se(ti( 1 1 iv, 171 at Y. hk d Kitoh enlarged to show char- 

 acter of the bacterial rot The tis^^ue ot the attacked pait A' did not hold the stain. 



(greatest observed variation in diameter 0.6 to 0.9m, usual 

 diameter 0.7 to 0.8^), growing on the surface of agar-poured 

 plates in the form of round, raised, smooth, gray-white, wet- 

 shining colonies (2 days) having entire well-defined margins 

 and a transient flaky areolation (XlO) with a slight fluo- 

 rescence, the buried colonies being globose, oblong or spindle- 

 shaped with irregular margins (X125), but, if thin sown, 



1 Repeated in 1919 in potato juice in fermentation tubes with contradictory 

 results, using Jones 3a (branched) and also 3a received from Wisconsin in 1920. 

 The latter sometimes gives a little gas and at othertimes not. 



