The Origin of Life 35 



is that spores of many bacteria have a size of 0.0003 or 

 0.0002 mm., and there are no doubt much smaller germs 

 which our microscopes fail to disclose. 



This assumption is undoubtedly correct. 



We will, in the first instance, make a rough calculation 

 of what would happen if such an organism were detached 

 from the earth and pushed out into space by the radiation 

 pressure of our sun. The organism would first of all have 

 to cross the orbit of Mars; then the orbits of the smaller 

 and of the outer planets*. . . . The organisms would cross 

 the orbit of Mars after twenty days, the Jupiter orbit after 

 eighty days, and the orbit of Neptune after fourteen months. 

 Our nearest solar system would be reached in nine thousand 

 years. 



For the assumption of eternity of life only the transfer- 

 ence of germs from one solar system to another would 

 have to be considered and the question arises whether 

 or not germs can keep their vitality so many thousands 

 of years. Arrhenius thinks that this is possible on 

 account of the low temperature (which must be below 

 —220° C.) at which no chemical reaction and hence 

 no decomposition and deterioration are possible in the 

 spores; and on account of the absence of water vapour. 

 The question then arises : Have we any facts to war- 

 rant the assumption that spores may remain alive for 

 thousands of years under such conditions and retain 

 their power of germination? We know that seeds 

 have a very limited vitality, and the statement that 



