647 



PART V. 



CONDITIONS AFFECTING THE DEATH OF THE LOWER 

 FUNGI. 



Various external influences cause injury to the lower Disinfection. 

 fungi, and affect their vital activity more or less pro- 

 foundly. All these injurious factors are evidently of 

 great interest, hecause we must search among them for 

 the means to enahle us to oppose the grave dangers 

 which threaten us on the part of the fungi, namely, the 

 infective diseases; and the whole of the influences 

 which alter the normal life of the lower fungi are 

 usually considered together under the heading " Modes 

 of Disinfection." 



Very numerous experiments have heen already made Difference in 

 with regard to the mode and the degree of action of the means ac- 



disinfecting means ; these must, nevertheless, be still ^^Jf the 

 greatly expanded. For just as in the study of the fungus. 

 biological characters of the fungi, so in this case it has 

 been found that the various species do not behave in 

 the same manner, but that the one is most markedly 

 affected by this influence, the other by that ; and that, 

 further, the sum total of the other conditions of life 

 which are present influences the action of the individual 

 disinfecting means. High temperatures injure the fungi According to 



v? , ! -, . , J B x the other con- 



more readily when bad nutrient materials are present at ditions of life. 

 the same time ; the active dose of specific poisons varies 

 according as the external conditions represent the op- 

 timum or vary from the optimum. The stage of deve- 

 lopment of the bacteria has also a marked influence 

 on their resisting power ; young individuals as a rule 

 are more resisting, while older individuals which are 

 approaching the stage of involution can be destroyed 



