30 



OBSERVATIONS. 



exuviae of animals : they cannot, therefore, be satisfactorily studied in 

 cabinet collections. Were any botanist, well acquainted with vegeta- 

 ble physiology, to devote some time to exploring the vegetable re- 

 mains, as they are abundantly brought up by our coal-miners, they 

 might have the opportunity of re-constructing many entire species 

 from the fragments ; but, in order to form a geological classification 

 of fossil plants, a practical acquaintance with all the secondary strata 

 is further required. The attempt of M. Adolphe Brongniart to give a 

 geological classification of the famihes of plants peculiar to each prin- 

 cipal formation, is entitled to high commendation, as the nearest ap- 

 proximation to a correct arrangement of fossil plants that has yet been 

 made. See his ^^Histoire des Vegetaux fossiles,^^ and his " Prodrome 

 d'un Histoire desVegetaux fossiles." 



