440 



Profs. Percy Frankland and Marshall Ward. 



The rate of growth was now so rapid I could no longer measure. 

 Doublings : 



218-0436 -0 fj. = 7.49 P.M. 8.41 P.M. = 52 minutes at 23 '023 -5 C. 



And back : 

 517 '5 258 -75 p = 7.59 P.M. 8.54 P.M. = 55 minutes at 23 -023 '5 C. 



On November 23 spores in normal gelatine were put in at 22 C. at 

 2 P.M., and observations at 25 started at 6 P.M. 

 Doubling : 



18 -036 -0 p. = 6.5 P.M. 6.39 P.M. = 34 minutes at 23 '5 25 -024-75 C. 

 36 -072 -0 = 6.39 7.30 =51 24 -75 25 -0 C. 



Calculated back : 



87 -5 43 -75 n = 6.56 P.M. 7.40 P.M. = 44 minutes at 24 -7525 -0 C. 



43 -7521 -75 = 6.16 6.56 ., = 40 24 -7525 '024 -75 C. 



Normal doubling period : 

 28 -056 -0 /* = 6.30 P.M. 7.16 P.M. = 46 minutes at 25 '024 '7524 -9 C. 



Another culture, made at 2 P.M. and hitherto at 22 C., was put 

 in at 8.40 P.M. 

 Doubling : 



195 -75391 -5 yu = 8.45 P.M. 9.31 P.M. = 46 minutes at 2325 C. 



Back : 

 490 -5245 '25 /x = 9.2 P.M. 9.45 P.M. = 43 minutes at 24 '625 -2525 '1 0. 



Normal doubling period : 

 245 -5490 -5 M = 9.2 P.M. 9.45 P.M. = 43 minutes at 24 -625 -2525 -1 C. 



A curious phenomenon is often observed in these stiff gelatine 

 cultures at temperatures near 23 24 C. This is the neighbourhood 

 of the melting point, and it sometimes happens that as the drop melts 

 the rate of growth rises quite sharply ; I explain this as due to the 

 sudden access of more oxygen and available food-materials to the 

 rodlets. 



