[HARRISON] VISCOUS FERMENTATION OF MILK AND BEER 87 



The thermal death point was 10 minutes at 60° C. for old and 

 young cultures. 



Coverglass preparations kept in broad daylight were killed in 13 

 days. When kept in the dark, they remained alive for 25 days. 



Cultures were dead at the end of 8 months. 



Further biological data of these two varieties, particularly with 

 regard to gas production, is given in the Centralblatt fiir Bakteriologie 

 II, Abte., 1905, 14, p. 359. 



Group IV. Varieties 9 and 10. 



Morphology. — ISTon-motile cocci or coccoid bacteria which occurred 

 in irregular masses, and occasionally in short chains. The cells were 

 either exactly round or a little longer than wide. The latter indi- 

 viduals often showed a clear centre space which did not stain. These 

 long forms looked like round-ended bacteria, and, as they were much 

 more numerous than round ones, these organisms must be considered 

 as bacteria and not as true cocci. They varied in size from .8 to 1.2 //. 

 They did not accept Gram's stain. 



Gelatine plate cultures. — In 24 hours small grey points appeared, 

 which quickly grew larger, became raised, shiny and viscous. The 

 border of the colony was slightly lobate and the centre pale yellow in 

 colour. The mature colony was 3 to 4 mm. in diameter. The colonies 

 developed a bad smell. 



Microscopical. — Young cultures were round and homogeneous, 

 later they became granular, and finally the centre part turned opaque. 



Deep colonies when young were granular and roimd, later they were 

 slightly irregular and opaque. 



Gelatine stick cultures. — The growth in gelatine stich cultures 

 resembled that of varieties of Group 1. 



Gelatine streak cultures. — Along the line of inoculation a good 

 growth developed and spread over the greater part of the surface. The 

 centre portion became shiny and raised, but the edge remained thin, 

 smooth and irregularly lobate. The odour of the culture was bad. 



Agar plate and streak cultures resembled the varieties of Group I. 

 The old agar cultures were exceedingly viscous and firmly adherent to 

 the medium. 



Potato. — On potatoes a fairly thick growth developed with an even 

 surface, shiny when young, but becoming dull and paste-like after 3 to 

 4 days. The growth was viscous. 



