BIOGENESIS AND ABIOGENESIS 125 



the consideration of this very important and 

 much discussed question. It has been sug- 

 gested that living matter might have been 

 brought to this world from some other by means 

 of a meteorite. This was the suggestion put 

 forward, amongst others, by the late Lord 

 Kelvin, one of the most distinguished physicists 

 the world has ever seen. He declared that 

 " dead matter cannot become living without 

 coming under the influence of matter previously 

 living. This seems to me as sure a teaching 

 of science as the law of gravitation." 



Hence * after alluding to the collisions be- 

 tween heavenly bodies and the projection 

 through space of some of their fragments he 

 says : " Because we all confidently believe that 

 there are at present, and have been from time 

 immemorial many worlds of life besides our 

 own,f we must regard it as probable in the 

 highest degree that there are countless seed- 

 bearing meteoric stones moving about in space. 

 If at the present instant no life existed upon 

 this earth, one such stone falling upon it might, 

 by what we blindly call natural causes, lead to 

 its being covered with vegetation." So distin- 

 guished a physicist as Lord Kelvin cannot have 



* Address to British Association, 1871. 

 t It ought to be added that this confident belief on the 

 p{ rt of Lord Kelvin was not and is not shared by all men of 

 science. See Wallace's Man's Place in the Universe (Chap- 

 man & Hall, 1904) for a discussion of this question. 



