1 84 THE BORDERLAND OF SCIENCE. 



a possibility that some worlds may come into collision 

 and be destroyed, it assuredly cannot be predicated as 

 a certainty respecting any given world our own for 

 example that it will be destroyed by collision at some 

 future date, however distant. Amidst the star-depths, 

 with their uncounted millions of suns each, perhaps, 

 tile centre of a scheme no less important or even more 

 important than our solar system where does Sir W. 

 Thomson find the suns which, by their dangerous 

 proximity to each other, seem to countenance his 

 hypothesis ? Not surely among the double, or multiple 

 stars ; for whatever collisions may occur among their 

 dependent orbs must be regarded as mere family contests 

 not competent to affect other systems. Where then? 

 Astronomy answers confidently that there is no evidence 

 of the sort. 



But let us grant, for a moment, that our earth has 

 come into collision with another world, and that many 

 great and small fragments carrying seed, and living 

 plants and animals, are scattered through space by the 

 collision, and let us endeavour to ascertain the con- 

 ditions under which one of these fragments may carry 

 the germs of life to some distant world. It need scarcely 

 be said that the living plants and animals would quickly 

 perish, so that we have only to consider the possibilities 

 relating to the vegetable germs. Now we have no 

 means of determining exactly how long a vegetable 

 germ may retain potential life. Corn-seeds from the 

 Pyramids have germinated, under suitable conditions, 

 here in England, and in our own age ; and it is con- 



