156 THE OCEAN 



While bacteria are usually killed by a 

 temperature of 140° F., they become merely 

 quiescent by repeated freezings, and survive 

 very low temperatures. If the temperature 

 sinks below a certain point organic substances 

 cannot putrefy ; when the frozen Siberian 

 mammoths were discovered, their flesh was 

 so little changed that it was eaten by the 

 hunters' dogs. If bacteria did not exist in 

 the cold water of the deep sea it would be 

 difficult to understand how the soft parts of 

 whales and fishes have undergone decom- 

 position. 



Phosphorescent bacteria are abundant in 

 the ocean, indeed they seem to be limited to 

 ocean water, for they have never been observed 

 in fresh water. These bacteria are present 

 on dead fishes and other marine organisms 

 at all temperatures, but especially at relatively 

 high temperatures. 



