CONDITIONS OF LIFE OF THE FISSION FUNGI. 539 



days. At 21 C. spores had formed after 72 hours, at 

 25 C. after 35 to 40 hours, and between 30 and 40 C. 

 after about 24 hours ; the best and strongest cultivations 

 were obtained between 20 and 25 C. In the case of 

 bacillus subtilis spore formation did not occur below 

 6 C., at 18-75 C. it required two days, at 22'5 C. 

 one day, and at 30 C. 12 hours. 



As regards the germination of spores, and the neces- Germination 

 sary conditions for that act, we have as yet no detailed 

 observations. A certain amount of water and a fairly 

 high temperature, differing, however, according to the 

 species, must be reckoned as absolutely essential con- 

 ditions. In the case of bacillus subtilis, the optimum 

 of the temperature for germination lies between 30 and 

 35 C., and in the case of anthrax bacilli at about 35 C. 



As regards oxygen it has been made out in the case of 

 the spores of some bacteria, for example of bacillus 

 butyricus, that it may actually hinder the occurrence of 

 germination ; while, as a rule, the entrance of oxygen is 

 just as necessary for the sprouting of the great majority 

 of the spores of bacteria as it is for those of yeast and 

 mould fungi, and as it is for the other functions of the 

 same bacteria. 



