THE EARTH 147 



conditions of the world as to result in similar organic 

 life. Even if the conditions are far from identical, 

 yet they may favour some kind of conscious or 

 unconscious molecular growth and activity compar- 

 able to the animals and plants of the world. 



On a question so speculative there are naturally 

 different opinions. 



" Supposing," wrote Tyndall, " a planet carved 

 from the Sun, set spinning round an axis and re- 

 volving round the Sun at a distance from him 

 equal to that of our Earth, would one of the con- 

 sequences of its refrigeration be the development 

 of inorganic forms ? I lean to the affirmative." 



Dr H. H. Turner, Professor of Astronomy in 

 the University of Oxford, stated in a lecture at 

 the Royal Institute : To the question. Are the 

 planets inhabited ? his answer would be that, in 

 the absence of evidence, he did not know, but that he 

 felt pretty sure they were, because they were so like 

 the Earth in so many particulars that they might 

 be supposed to be Hke it in this one. 



M. Camille Flammarion wrote in Knowledge : 

 " Yes, life is universal and eternal, for time is 

 one of its factors. Yesterday the Moon, to-day 

 the Earth, to-morrow Jupiter. In space there are 

 both cradles and tombs." ' * 



On the other hand, Dr A. Russell Wallace, 

 who has made a special study of the question. 



