290 ANNUAL EEPOET SMITHSONIAN INSTITUTION. 1918. 



tion of individuals and of floras, their interactions with an ever- 

 changing environment, and the transmutation of these facts into 

 terms of ancient geography, topography, rainfall, temperature, and 

 distribution. 



The scientific study of fossil plants is a very modern development, 

 for, notwithstanding the great abundance of fossil plants in the 

 countries of the classical world surrounding the Mediterranean, the 

 limestone quarries of the Greeks, the petrified forests of Nubia, and 

 the vast public works of Imperial Rome, none of the writers of 

 antiquity mention fossil plants, although some of them carried on 

 a lively discussion regarding the nature of animal fossils. Petrified 

 wood is not recorded until about the middle of the thirteenth cen- 

 tury (Albertus Magnus), and fossil foliage not before the latter 

 half of the seventeenth century (Major, Lhwyd). The earlier com- 

 mentators explained fossils as due to the mystical action of the stars 

 or the mysterious working of spiritual forces like the vis lapidifica 

 of Avicennia, or the virtus formativa of Albertus Magnus, or the 

 stone-making spirit of Sperling. Nothing was further from the 

 accepted thought than that fossils were the remains of real organ- 

 isms that had once lived; the nearest approach to such a view was 

 that they were some of the models used by the Creator or that they 

 had developed from abortive germs of animals and plants that had 

 become lost in the earth. 



After the view that fossils were the remains of organisms had 

 gained many adherents, they were regarded as evidence of the uni- 

 versal deluge — an interpretation suggested by Martin Luther in 1539. 

 This flood theory or diluvial hypothesis found numerous advocates 

 throughout the seventeenth and even far into the eighteenth century. 

 For example, in the Transactions of the Royal Society for 1757, 

 James Parsons figures numerous fossil fruits from the early Eocene 

 deposit of Sheppey in the Thames estuary. These, he thought, 

 would furnish evidence of the season of the year in which Noah and 

 the rest of creation were obliged to take refuge in the ark, and he 

 concludes from the maturity of these fossil fruits that the deluge 

 commenced in the fall of the year and not in the spring, as his con- 

 temporary, Doctor Woodward, had supposed. Johann Jacob Scheuch- 

 zer (1671-1738) was the great exponent of the flood theoiy, pub- 

 lishing his Herbarium Diluvianum at Zurich in 1709, and even figur- 

 ing the bones of one of Noah's less fortunate brethren which he found 

 among the fossil leaves at Oeningen on the Swiss border of Baden, 

 and which subsequently proved to be the bones of a large Miocene 

 amphibian. 



The flood theory passed through various phases of opinion. At 

 first the fossil plants Avere regarded as similar to those still growing 

 in the vicinity — a natural enough belief when the universal accept- 



