680 THE UNIVERSE. 



The supporters of the unlimited dissemination hypothesis 

 did not stop here : one absurdity brings others in its wake. 

 Some of them, falling back into the conceptions of the her- 

 metic philosophy, constituted these germs imperishable 

 metaphysical entities, descended, according to them, from 

 the Mosaic creation, capable of traversing ages and cata- 

 clysms, and arriving at our epoch full of fecundity and life. 



All this was the result of one false idea ; for if the air 

 were filled with all the generative elements which would be 

 necessary to its part of universal dissemination, it would be 

 so thick that we could not move about in it, and we should 

 be plunged in the most profound darkness. In fact, if some 

 globules of the vapor of water are sufficient to produce thick 

 and choking fogs, which, as at London, often force us to 

 have recourse to links in mid-day, what would the atmos- 

 phere be if it were loaded with eggs and seeds ? 



The name of panspermism has been given to this pre- 

 tended universal dissemination of the reproductive bodies 

 of animals and plants. But this perfectly gratuitous hy- 

 pothesis falls so soon as it is submitted to the criterion of 

 observation. 



There a replants which only appear under circumstances 

 so exceptional and so extraordinary that the mind revolts 

 at the idea of their tiny seed loading the atmosphere for 

 century after century, in order, at long intervals, to fertilize 

 some imperceptible part of the globe. This would be in- 

 utility in immensity. 



A fungus is known, which never grows except on the 

 bodies of dead spiders ; another only appears on the surface 

 of horses' hoofs in a state of putrefaction. One little para- 



