526 Lindley and Hutton's Fossil Flora. 



we present the following abstract : — First, an extract from 

 Brongniart's Prod., p. 181., is given, in which Brongniart has 

 expressed opinions to the amount that the plants which, in 

 their fossilised condition, constitute the coal measures, had 

 grown in a hot, insular, and humid atmosphere, and this on 

 the facts that the fossil species which had been determined 

 were mainly of the families ferns and Lycopodiaceae ; and that 

 in the living plants of the world, in the present era, the 

 numerical proportion of the species of plants of these fami- 

 lies, as compared with the number of phanerogamous species, 

 in any site considered, had been found to rise correspondently 

 to the condition of that site in insularity and the extent of the 

 temperature and moistness of its atmosphere. Professor Lind- 

 ley has opposed to these opinions the following facts and con- 

 siderations : — " It . . . always appeared to me very doubtful 

 whether such data as we possessed concerning the flora of 

 the coal measures could be considered of a nature sufficiently 

 precise to justify geologists in entering into such calculations, 

 in which, for them to be of any value whatever, a full know- 

 ledge of all facts is obviously indispensable. It was, more- 

 over, perfectly clear that the numerical proportion borne by 

 ferns to other plants was rapidly diminishing as the examina- 

 tion of the vegetable remains of the coal measures became 

 more carefully conducted. The very remarkable fact, that 

 ferns are scarcely ever met with in fructification in a fossil 

 state, was also a circumstance upon which no light was thrown 

 by the theory of a high temperature and damp insular at- 

 mosphere. Taking all these into consideration, along with 

 the constant state of disintegration of vegetable remains — a 

 disintegration unquestionably not the result of drifting, — I was 

 led to suspect that, possibly, the total absence of certain kinds 

 of plants, the as constant presence of others, and several other 

 points of a like nature, might be accounted for by a differ- 

 ence in the capability of one plant beyond another of resisting 

 the action of water. Accordingly, on the 21st of March, 

 1833, I filled a large iron tank with water, and immersed in 

 it 177 specimens of various plants, belonging to all the more 

 remarkable natural orders, taking care, in particular, to in- 

 clude representatives of all those which are either constantly 

 present in the coal measures, or as universally absent. The 

 vessel was placed in the open air, left uncovered, and left un- 

 touched, with the exception of filling up the water as it eva- 

 porated, till the 22d of April, 1835; that is, for rather more 

 than two years. At the end of that time, what remained was 

 examined, with the results stated in the following list." 



[For this list we refer to the Fossil Flora, No. xvii. We 



