6o ETERNITY OF LIFE 



The distance separating one planetary system from another 

 is tremendous. Even if the particles were to travel at the 

 speed already mentioned it would still be many thousands 

 of years before they reached the nearest star. Under these 

 circumstances one must take into consideration all the 

 dangers to which the germs of life would be submitted 

 during the whole course of their long journey, the severe 

 cold of interstellar space, the complete absence of moisture, 

 oxygen, etc. Could they endure all these hardships for thou- 

 sands of years while still retaining the ability to multiply 

 when they fell on a new planet, and to give rise to all the 

 later inhabitants of that planet? 



The state of the problem 

 at the present day. 



The adherents of panspermia expended much work and 

 ingenuity to prove the possibility of such a passage of the 

 germs of life from one heavenly body to another in a viable 

 condition. The spores of bacteria are, in fact, extremely 

 stable under all sorts of unfavourable external conditions. 

 Many of them certainly do not need oxygen. It is well known 

 that anaerobic bacteria can not only be conserved without 

 oxygen but can live without it for the whole of their lives. 



In the absence of water due to partial, or even more so 

 to complete, drying, living processes are brought to a stand- 

 still but the organism is not by any means always killed. 

 It only goes into a state of anabiosis. This is generally known 

 in the case of the seeds of plants and even such lower animals 

 as rotifers, tardigrada and eelworms. The extensive literature 

 concerning this question is collected in P. Shmidt's book 

 Anabiosis. ^'^ The spores of bacteria are particularly resistant 

 to drying. At the beginning of the century L. Maquenne^"* 

 showed that it is even possible to keep absolutely dry seeds 

 in a vacuum for many years and that under this treatment 

 they do not lose their viability. This was later confirmed by 

 P. BecquereP^ and a number of other authors. 



The resistance of bacteria and their spores to low tempera- 

 tures appears to be exceptional. R. Pictet^* pointed out 

 this peculiarity of bacteria in the nineteenth century. P. 



