550 ANNUAL EEPOET SMITHSONIAN INSTITUTION, 1912. 



scientist has made a series of researches in the course of which spores 

 in a vacuum have resisted/or several months the ilhimination of a very 

 strong solar light which, had they been in the air, would undoubt- 

 edly have killed them. 



So one can conceive that a living germ, wandering through space 

 and coming from a body on which life has already been manifested, 

 can travel for a long time, meanwhile escaping causes of destruction 

 that surround it, and arrive on a world still devoid of life, where 

 conditions of temperature are such that life begins to become pos- 

 sible there. 



It is enough that among the thousand millions of thousand mil- 

 lions of germs sent off into the infinite by the pressure of radiation, 

 a single one shall reach a planet that has been without life up to 

 that time, in order to become there the point of departure of mani- 

 fold organisms that will slowly evolve from it. The minuteness of 

 such a germ moderates its fall through the atmosphere of this planet 

 enough so that it does not become heated as a result of its friction 

 in the atmosphere to a temperature sufficient to kill it. Having 

 entered the atmosphere of the new planet, it will follow its eddies 

 and currents, it will fall on a substratum, either solid or liquid, which 

 will offer it the ''optima" conditions of development, life wUl be 

 born on the surface of a world lifeless till that time. "And, even if 

 there should elapse millions of years between the moment when a 

 planet is susceptible of carrying life and the moment when a germ first 

 falls upon it and develops there in order to take possession of it 

 for organic life, that is very little in comparison with the extent of 

 time during which this life will be able to exist there in complete 

 development."^ 



And so, according to this magnificent conception of the Swedish 

 physicist, life can be carried from one planet to another. Germs 

 swept away by ascending air currents which carry them to the lim- 

 its of the atmosphere are repelled by the electrically charged dust 

 that has penetrated there, coming from suns that have driven it away 

 by the repelling pressure of their radiation. After they have arrived 

 in space they attach themselves to some straying grains of dust of 

 greater dimensions than theirs and consequently capable of obeying 

 the attraction of a neighboring planet rather than the repelling force 

 of radiation; they then penetrate into the atmosphere of this new 

 planet and bring life to it, if life has not yet developed there. 



And in that case one is forced to the conclusion that if all beings 

 that live on a certain planet are derived from one initial germ, they 

 have been able to reproduce in their almost infinite variety only by 

 the evolution of forms that can have come from this original germ. 



> Arrh^nius, ibid., p. 241. 



