ZOOLOGY AND MOTANY, MICROSCOPY, KTC. 



441 



The author gives a modification of the numerical system used by the 

 Society of American Bacteriologists for comparing the characters of ropy 

 milk organisms, and also the following example of the method of using 

 the system. 



Large coccus, about 2 ix in diameter. 



SmaU „ ,, 1 ^ 



Streptococcus. 



Short rod. 



Loug rod, 1 ju X 2 ^. 



Slightly curved rod. 



Oval cocci, 1'2 /i X 2*1 /i. 



Endospores produced. 



,, not produced. 



Motile. 

 Non-motile. 

 Ropiness due to swollen capsule. 



,, ,, slimy protein substance. 



,, ,, non-protein nitrogenous body. 



,, „ enormous number of organisms. 



No capsule produced. 

 Aerobic. 



Facultatively anaerobic. 

 Gelatin liquefied. 



„ not liquefied. 

 ,, colonies white and shining. 



,, ,, small and opalescent to transmitted light. 



Produces a wide range of colours — blue, etc. 

 White colonies, brownish to transmitted light. 

 Liquefying colonies, like hay bacillus. 

 Gas produced in milk. 

 No gas produced in milk. 



Produces a yellowish-green curd on surface of milk. 

 Ropiness strong and permanent in milk. 



,, weak, but ,, ,, 



,, weak ; passes off in time. 



,, permanent grey or green-blue produced in 40 hours. 

 All casein disFolved ; liquid, yellow, and slimy. 

 Makes milk ropy at room temperature under 5 hours. 



1 '^ 



>? ») n M -*-^ M 



90 

 '> I) )> I) •^"-' i> 



M M »l )) *'^ )) 



J J ) J J » ) J ^O , , 



,, ,, ,, moderately rapidly (2 days). 



„ „ ,, slowly. 



Example of Method of using the Numerical System. 



Bacillus lactis viscosiis Adametz, 5211-122213. 



5000 The organism is a short rod. 



200 Endospores are not produced. 



10 It is motile. 



1 Ropiness is due to a swollen capsule. 



0*1 The organism is aerobic. 



0*2 Gelatin is not liquefied. 



0'002 Colonies on gelatin are small and opalescent to transmitted light. 



0-0002 No gas is produced in milk. 



0-00001 Ropiness is strong and permanent in milk. 



0-000003 Milk is made ropy in less than 15 hours at room temperature. 



Aug. 21st, 1912, 



2 H 



