Report on the Bacteriology of Water. 



337 



wen 



10 M It I I 9 4 9 



1,400 



1,100 



1000 



900 



800 

 700 

 600 



500 



400 



300 



ZOO 



/MOO 



Temp 



MIA 



curvi 3 dui 



n I+K epon 



T imp. SB. 



sTage 



_pq ure. ij ' 



/'" 7 / 



spun 7 



and eventually grew into normal and rapidly-spreading filaments ; 

 but the effects of the retardation and weakness were evident in the 

 poverty and lateness of its spore-formation. 



I repeated the foregoing experiment the next day, which was also 

 sunny and with a blue sky with passing white clouds, under exactly 

 the same conditions, excepting that the general temperature was 

 lower throughout and the sky less clear. The utmost care was 

 taken in the arrangements of the shutters, positions of microscope 

 mirrors, <fec., and no direct sunlight touched any of the apparatus. 

 The thermometer readings were as follows all with bulbs black- 

 ened : 



The readings show (1) that the temperature varied very slightly, 

 and (2) that of the red culture was a trifle higher than that of the 

 blue. 



The spores, which had been sown at 10 A.M., and exposed at 10.30, 

 were examined from time to time as before; and, also as before, 

 germination began in the red culture long before it did in the blue. 



After exposure for the day, I placed the cultures from 11 P.M. near 

 an open window, with a pair of maximum and minimum ther- 

 mometers by their side, in order to check the growth during the 

 night, because there was a danger of the red one forming filaments 



