LIVING SUBSTANCE 7 



ble of drying up also, and remaining in an apparently 

 lifeless condition for long periods of time, blown 

 about in the dust by the winds (fig. 1). Falling in 

 a favorable spot where there is sufficient water, they 

 " come to life again " and resume their activity 

 as if it had never ceased. The excessively minute 

 " germs " of bacteria keep the race in existence in 

 this way. 



In seeking an analogy to these phenomena a 

 German scientist, Preyer, has compared the plant 

 or animal to a clock, which goes through its charac- 

 teristic movements so long as the energy in its 

 mainspring lasts. It may be stopped and remain 

 so until its pendulum is set swinging again, in which 

 case it may be compared with a fertile seed. But 

 if its mainspring be broken or if it run down, even 

 though externally it be just the same in appearance, 

 it no longer " goes." Some such a difference as 

 this may exist, not to push the comparison too 

 far, between an organism in which life is merely 

 suspended and one that is dead. 1 



Our search, therefore, for the answer to the ancient 



1 Waller has shown that in such forms of living substance as nerves, 

 which do not contract or give any visible evidence of life or death, it is 

 possible by galvanometric test to show that a "live" nerve deflects the 

 needle, whereas a "dead" one does not; in other words that the electric 

 response is a very delicate and accurate sign of life. By this means he 

 claims to have been able to mark the "beginning of life" in an incubating 

 hen's egg. A Hindu physiologist, Professor Bose, has claimed, on the 

 basis of very careful experimental work, that this electrical sign of life 

 is dependent upon the "molecular mobility" of the matter, and that it 

 disappears when "molecular fixation" or strains ensue. Herein may be, 

 possibly, the simple difference between living and dead matter. 



