648 CONDITIONS AFFECTING THE DEATH OF FUNGI. 



According to by trivial and transient injuries. The effect of the 

 development, formation of spores is of very special importance. If 

 we have to deal with organisms which form these 

 extremely resisting bodies, means which would greatly 

 injure, or even destroy, other fungi may be entirely 

 without effect. Hence in disinfection experiments 

 spore-bearing and non-spore-bearing organisms must 

 not be mixed together, each must be tested separately. 



Among the means of disinfection we reckon not only 

 those which kill and destroy the organisms, but also 

 those influences which only cause a permanent loss or a 

 diminution in activity of some of their vital phenomena, 

 and even those which only occasion a temporary delay 

 in their growth and multiplication. These different 

 degrees of degeneration and death require a separate 

 discussion. 



Inhibition of 

 development. 



Inhibition of 

 individual 

 vital pheno- 

 mena. 



I. Inhibitory Means. 



The smallest degree of injury which micro-organisms 

 can experience, as the result of external influences, con- 

 sists in a disturbance of their complete development, 

 which only lasts so long as the injurious factors are 

 present, while afterwards under normal conditions the 

 ordinary vital phenomena can again go on undisturbed. 



Minute departures from the normal conditions of 

 existence often lead to cessation of some one biological 

 function. Thus by alterations in the nutrient substrata, 

 by diminution in the amount of oxygen, by a tempera- 

 ture somewhat too low or too high, we may have cessa- 

 tion of the swarming power, of the secretion of peptonising 

 ferments, of the fermentative action, of the production 

 of colouring matter, or of the spore formation ; while 

 otherwise growth, multiplication, and all other vital 

 phenomena remain unaltered. Their power in pro- 

 ducing disease also may be influenced by similar trivial 

 alterations in the conditions of life, and may even be 

 temporarily removed ; and it would be a matter of great 

 interest to learn more accurately the various means for 

 example, small doses of specific poisons, alterations in 



