GEOLOGY. 715 



them from the Mosaic creation, capable of traversing ages 

 and cataclysms, 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 giobvdes of the vapour 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 atmosphere be if it were loaded with eggs and seeds 1 



Tlie name of imnspermism has been given to this pre- 

 tended universal dissemination of the reproductive bodies 

 of animals and plants. But this perfectly gratuitous hypo- 

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

 observation. 



There are plants 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 



mala whicli are found on a large scale on our globe. An oak appears ti5 me com- 

 posed of plants, insects, shells, reptiles, fish, birds, quadrupeds, and even men. 

 I see innumerable germs rise into the roots with the juices designed for their 

 nutrition. I see them circulate in the different vessels and lodge in the thickness 

 of their membranes, in order to augment their growth in every direction." 



Who would believe then that such a science found supporters in the nine^ 

 teenth century ? Yet this has taken place. M. le Vicomte Gaston d'Auvray, in 

 order to save from shipwreck the old doctrine of jiansperraism, and the theories of 

 M. Pasteur, has assumed that there exist in the air myriads of eggs and spores, 

 the vitality of which resists boiling for eight hours and even a white heat. 



