Tenacity of Life 43 



(3) The third answer, associated with the names of 

 Kelvin and Helmholtz, Richter and Arrhenius, and 

 therefore not to be smiled at, is that minute living 

 organisms may have come to earth from elsewhere, 

 ensconced in a meteorite or wafted with cosmic dust. 

 There is the difficulty of understanding the survival 

 of germs after passing through extremes of tempera- 

 ture, but that would depend on how they were 

 wrapped up, and Becquerel's experiments show that 

 simple and quiescent forms of life can endure ex- 

 tremes of heat and cold. The chief objection to this 

 answer is that it merely shifts the responsibility of 

 the problem off the earth. 



It should be recalled that dried seeds may retain 

 their capacity for germinating even after four-score 

 years. Parsnip seeds may germinate after two years 

 in a vacuum. Some other seeds — e.g., of mustard and 

 wheat — will endure being subjected for three weeks 

 to the temperature of liquid air, and after that for 

 seventy-seven hours to the temperature of liquid 

 hydrogen, 250° C. below zero. Under the combined 

 influence of low temperature and great drought, the 

 living matter passes out of its normal colloidal state, 

 and yet the seeds show a high percentage of germina- 

 tions. As Becquerel says, "life without water, without 

 air, without gaseous interchanges, without colloid 

 molecules in suspension in a liquid, appears paradoxi- 

 cal," but it is a fact, and it should be borne in mind in 

 considering the suggestion that germs of life may 

 have come to the earth from elsewhere. Small Nema- 

 tode worms can remain in a state of latent life for 



