282 Durability of the Ferns. 



the water as it evaporated, till the 22d of April, 1835, that is 

 for rather more than two years. At the end of that time, what 

 remained was examined, and the following highly curious m. 

 suits were obtained. 



In the first place it was found that the dicotyledonous plants 

 had in general wholly disappeared ; whence it was inferred 

 that they could not remain for two years in water without be« 

 ing wholly decomposed. On the contrary, the principal part 

 of those found in an undecayed state, were the Coniferse and 

 Cycadese, which are the very individuals found best preserved 

 in the fossil state. 



Secondly, it seemed that monocotyledonous plants survived 

 to a considerable degree ; whence it was concluded, that they 

 are more capable of resisting the action of water, (the palms 

 in particular,) than the exogenous tribes, which agrees with 

 their fossil relics ; but the grasses and sedges had perished; 

 whence it was concluded that although none of these may be 

 found as fossils, still we have no right to infer that the earth, in 

 the primeval state, was not clothed with the grasses, since 

 there is reason to believe, that had this been the case, they 

 might have entirely disappeared. 



Thirdly, the fungi and mosses, and all the lower forms of 

 vegetation, were not to be found, and even the equisetums, 

 though of considerable size, left no traces behind 



Fourthly, the ferns appeared to have the greatest power of 

 all the plants tried, to resist the decomposing effects of water, 

 especially if immersed in the green state, for not one of them 

 had disappeared during the experiment ; there being no decay, 

 except that the spots of fructification had disappeared ; a re- 

 sult often, if not constantly, met with in the fossil state. 



From these experiments, Dr. Lindley assumes, as a general 

 result, that the numerical proportion of different families of 

 plants found in the fossil state, throws no light whatever upon 

 the ancient climate of the earth ; but that the species and num- 

 bers found, depend entirely upon the power which particular 

 families may possess, by virtue of the organization of their cuti- 

 cles, or otherwise, of resisting the action of the water in which 

 they floated previously to their being fixed in the strata in 

 which they are now found. 



