DISSEMINATION OF PLANTS. 255 



It is true that feeds which are buried to a certain depth will Could the feed* 

 be preferved for a great length of time, and being afterwards J 1 ** 6 b ^. n {o 

 fubmitted by culture to the action of the light and water, will 

 germinate. But is it to be prefumed, that the feeds of pur- 

 flane were preferved in the earth of the Antilles, during the 

 many ages the forefts had endured before they were deflroyed ? 

 Is it probable that, in the forefts of Gaul, whofe antiquity is 

 well afcertained, the feeds of thofe plants, which appeared 

 after they were rooted up, or after placing a charcoal furnace 

 in them, mould have been preferved found from before the 

 exigence of the forefts ? The diflemination of plants has ne- 

 ceflary limits ; beyond thefe, we mud have recourfe to other 

 explanations. 



Laftly, the plants of the clafs cryptogamia, and particularly Facts refpe&ing 

 fungi, whofe form is conftantly determined by the nature of the cryptogamia. 

 the fubftance on which they grow, and is conftantly the fame 

 in fimilar circumftances, although they do not appear at ftated 

 feafons like other vegetables, alfo prefent new fa6ts. It is not 

 long fince Cit. Ventenat obferved a boleta of a peculiar new 

 (hape, which was produced on a human body. I have noticed 

 the clavaria, which is conftantly formed on the cryfalides of 

 caterpillars (Journal de Phyf, Annee. 1787^ ; others grow on 

 thofe fruits which have a woody covering ; fuch as are formed 

 on the fragments of fir, are not the fame as thofe which grow 

 on the wood of the oak. The hufk of the nutmeg produces a 

 fungus peculiar to itfelf, (Ancienne Encycl. art. Mufcade). 

 Laftly, the fungi which are formed on the wooden props of 

 mines, cellars, &c. are not the fame as thofe produced by 

 the fame woods when they decay in the open air. It is dif- 

 ficult to conceive the diflemination of feeds from one mine to 

 another, particularly to thofe which are opened in fituations 

 where no mines had exifted before ; neverthelefs I have found 

 all thofe which I have examined in different countries to pof- 

 fefs very nearly the fame form. 



All thefe confiderations may induce us to prefume, that na- j t j s preAxmed 

 ture is daily exercifing the fame powers which (lie poifefled at that plants con- 

 the creation, and it would be interefting to examine the foJJJJJJSi^ 

 caufes and afcertain the means of execution ; but this can only propagation. 

 be the confequence of long and diverfified investigations, car- 

 ried on by a great number of obfervers. 



An 



