PHENOMENA AND CONDITIONS OF LIFE 41 



anthrax are killed only after having been exposed for three hours 

 to a heat of 140 C. Even seeds of grass and corn, which had 

 previously been desiccated, sustained for hours a dry heat of 

 100 to 110 C. without losing their power of germination. 



A similar tenacity is displayed by many of the lower organisms 

 in the presence of cold. According to MacFadyen and others, 

 certain species of bacteria survived being exposed for seven days 

 to a temperature of- 190 to -225 C. 



That many multicellular organisms are almost insensitive to 

 rapid changes of temperature is shown by the behaviour of the 

 ' gutter-fauna,' in particular, the Wheel and Bear-animalcules. 

 We are not only able to expose these delicate organisms to severe 

 frost, but also to a heat of over 100 C., and yet revive them by 

 restoring the normal conditions of their life. 



One might think that such extraordinary tenacity is specific 

 only to the simplest and lowest organisms. In a certain sense 

 that is true, for sensitiveness to external influences increases 

 with increasing differentiation, a fact that may be observed 

 in everyday life. The coarse strength of the robust country- 

 man will easily endure hardships under which the more finely 

 organized and therefore more delicate townsman collapses. But 

 the countryman is denied many pleasures which to the more 

 highly differentiated townsman are his ' real life.' Thus everything 

 in the organic world is interdependent, and each ' higher ' in one 

 regard is balanced by one * lower ' in another. In natural science 

 we should not, therefore, speak of higher and lower organisms, 

 but of simple and complex. Indeed, if we took the degree of 

 success in adaptation as our standard we should have to regard 

 protozoa and bacteria as the highest and most perfect organisms. 



Turning for a brief moment to the vertebrates, we find among 

 them similar cases of great resistance to unusual external con- 

 ditions. Like a romance sounds the history of a newt, as related 

 by Erber. Destined to serve as food for a snake, it had suc- 

 ceeded in escaping its intended fate, and was found many weeks 

 after in a corner of the room, completely shrivelled up. Placed 

 in its natural element it revived rapidly, ate well, and soon 

 regained its original appearance. But there was worse in store 

 for the newt, for an unexpected night-frost came, froze the water 

 in the aquarium, and the next morning found the newt frozen 



