INFLUENCE OF TEMPERATURE 221 



Dry spores will resist still higher temperatures than moist spores. 

 Some dry spores survive an exposure to 140° or 150° for ten minutes. 

 It requires a very high temperature to sterilize glass, cotton, gauze, and 

 instruments with dry heat. A discontinuous steriUzation of dry mate- 

 rial is useless, since the spores will not germinate without moisture, 

 therefore their resistance remains unaltered. 



The spores of molds are more resistant than the mycelium, but if 

 moist, they all die at 100°. The dry mold spores can tolerate a some- 

 what higher temperature, but not as high as the spores of many bacteria. 

 Yeast spores and yeast cells are very much alike in their resistance to 

 heat. The table on page 220 shows hardly any difference between their 

 resistance. 



