Report on the Bacteriology of Water. 443 



Another filament was taken at 8 P.M. and measured as follows : 

 Doubling period : 



225450 n = 8.13 P.M. 8.55 P.M. = 42 minutes at 25 '425 '9 C. 



Beckoned back : 



486243 n = 8.17 P.M. 8.59 P.M. = 42 minutes at 25 -426 '0 C. 



The following case is a very interesting one. It will be noticed 

 that a drop of KHO was put into the arm of the cell. I was experi- 

 menting at the time to see if I could detect any difference by 

 removing what traces of C0 a diffuse into the cell as fast as they 

 form, but the results were negative in that connection. Incidentally, 

 however, it turned out that the drop of strong KHO often caused a 

 slight dry skin to form on the gelatine drop when first put into the 

 higher temperature, the skin being visible by faint wrinkles in it, 

 and this affects the growth of the organism, possibly by impeding 

 oxygen access. After the drop had melted, all went on quite normally, 

 as we see, and there is no reason to reject the curve as an illustrative 

 one. 



On November 10 spores were sown at 10.30 in 10 per cent, gelatine 

 and put into 22 C. A drop of KHO was put in the arm of the cell. 

 At 3.35 the culture was put into Sachs' box at 27'5 C. The opened 

 box fell to 25 C., but recovered to 27 C. at 3.45. 



The filament selected did not grow very straight at first, but 

 straightened out later and did well ; it was also abnormal in some 

 way, having one joint swollen, but recovered eventually, and after 

 three-quarters of an hour or so behaved quite normally, and the 

 question arose (answered above), had the KHO any effect ? 



The doubling periods here : 



4692 n = 4.0 P.M. 4.52P.M. = 52 minutes at 27 -2 27-0 27-5 C. 

 92184 = 4.52 5.36 = 44 27 '527 '927 '75 C. 



Beckoned back : 



243-0121-5 /x=5.11 P.M. 5.53 P.M. = 42m. at 27 '7527 '927 '752827 '6C. 

 121-5 60-75 ,, = 4.33 5.11 =38 27 '0 27 '9 C. 



Normal doubling periods : 



48 96 n = 4.5 P.M. 4.55 P.M. = 50 minutes at 27 '027 '5 C. 

 96- 192 ,, = 4.55 ,,5.40 =45 27 '5 27 '9 C. 



I regard the first period of growth as unmeasurable and abnormal, 

 due to something wrong with the growth and position of the filament, 

 but after the first hour it seemed quite normal, as said. 



A second filament from the same culture was then examined, as 

 follows : 



2 H 2 



