( 247 ) 8^S 



Note^ by M. Alphonse de Caxdolle, concerning M. Marcel 

 cle Sevres's Essay upon the Question^ Whether the Ejcamina- 

 tion made, in the Coaljbrmation of Canada and Baffin's Bay, 

 of Plants analogous to those which now flourish in Equatorial 

 Regions, proves a Change in the Inclination of the Ecliptic,''^ 



Having become acquainted with the memoir of M. Marcel 

 de Series, when it was passing through the press, I take the 

 liberty of offering some reflections which suggested themselves 

 during its perusal. 



The author commences by attributing to me the theory, more 

 or less ingenious, which he combats ; but if I have had the 

 humble merit of making it known to Frenchmen, 1 must here 

 repeat, what I formerly distinctly announced, that I received it 

 from Messrs Hutton and Lindley, the conductors of " The 

 Fossil Flora of England^'' 



As to the gist of the question, I must observe that M. Mar- 

 cel de Serres has denied two laws in physiological botany, in 

 which there are now but few doubts ; and which, if opposed, at 

 least merit to be combated with new facts. The one of them 

 is the permanency of species ; that is to say, the hereditary 

 nature of forms, \\\ which there is an accurate resemblance of 

 individual plants to those from which they have been produced, 

 whatsoever their external circumstances may be : and the other 

 is, that those plants which may be referred to the same genera 

 or families can live only under analogous conditions, as to soil, , 

 heat, light, and humidity. Let any one descend into a deep 

 mine, and he will there find some of the inferior ferns and lyco- 

 podinea3 only : or let him reflect upon the important action of 

 light on the respiratory and exhaling functions of vegetables, and 

 it will then be scarcely possible for him to believe that the plants 

 which are organized, as are those of our equatorial regions,— 

 plants which do not cast their leaves, and which open their 

 stomates, under the direct influence of the sun, twelve hours out 

 of the twenty-four, can support a darkness of several months^ 



• Marcel de Serres's paper is inserted in vol. xix. p. 64 of the Edin. New 

 Phil. Jour. 



