BACTERIAL DEfiTRlCTlON OF COPEPODH 225 



SESSIONAL PAPER No. 38a 



If the quantity of litmus added be more than IJ per cent the reaction is 

 quite different, varying according to the percentage of litmus added. There 

 may or may not be coagulation, the colour varying from Isabella to a muddy 

 purpureus; flakes of tinted curd can later be noted. In 2 months a condition 

 resembling broken jelly of a variety of shades of purpureus has been recorded. 

 A note referring to this phenomenon in greater detail is being published else- 

 where. 



AescuUn agar. — Growth moderate, flat, dry, brown to black. 



Neutral Bed Bile Salt Agar. — Growth scant, no characteristic colour reaction. 



Peptone Broth Aesculin. — Black in 12 hours. 



Gelatine Colonies — (1st appearance). — 21°C. 4 days, punctiform to pinhead colo- 

 nies, depression in medium commencing; under the low power objective struc- 

 ture compact, finely granular, paler towards the edges; edges ciliate. 



Agar Colonies. — 37° C. growth slow. 24 hours colonies -5 mm. in diameter, growth 

 tends to be subsurface. Under the low power objective colonies round or 

 eliptical, edges entire to undulate, internal structure granular, dark halo in 

 surrounding medium. 



Temperatui*e Belations. — 



Thermal death point. 10 minutes' exposure in nutrient broth at 60°C. 

 Optimum temperature. 37°C. ; cultures incubated at 37°G'., 21°C. and 14^0. 

 respectively. 



Vitality of Culture Media: — 



Active cultures have been recovered from agar tubes after 5 months at tempera- 

 ture of 15°-20°C. 



Relation to Oxygen. 



Facultative anaerobe. Under aiurrobic condition on glucose agar, growth visible 

 in 24 hrs. at 37°C. 



Biochemical Beactions: — 



Indol production : no indol in 7 days. 

 Reduction of nitrates: no reduction to nitrites. 

 Voges-Proskauer reaction: negative. 

 Methyl red reaction : acid to methyl red. 



Fermentathn of Carbohydrates : — 



Glucose. Lactose. Saccharose. Maltose. Mannite. Dulcite. 



+ + + + + 



Dextrin. Salicin. Raifinose. Adonite. Inulin. Xylose. 



+ + 



Glycerine. 



+ = acid. 

 ++ = acid and gas. 



In accordance with the cultural results this organism is properly included among 

 the liquefying streptococci. Winslow ^■^ takes the Str. gracilis of Escherich, Lehmann 

 and Neumann as the " type centre " of these liquefiers. He considers that the various 

 streptococci which peptonise gelatine more or less actively are variants of this type; 

 intermediate between it and some of those characterized by Andrews and Horder 3^. 



I find, however, a closer resemblance to an organism described by MacCallum and 

 Hastings"^ as Micrococcus zijmogenes. This was isolated from a fatal case of acute 

 endocarditis, and while it shows the same main characteristics as Str. gmvilis, it 



