INTRODUCTION. 13 



the desultory literary method of treating nature, to the more 

 direct, more exacting system of observation and description. 

 Plants, animals, and rocks were studied with enthusiasm, were 

 examined, described, figured, and classified, so that in a rela- 

 tively short space of time a fairly extensive botanical, zoological, 

 and mineralogical literature sprang into existence. 



Various Opinions about Fossils. The Greek and Roman 

 writers had correctly realised that fossils represented the 

 remains of animals and plants, and most of the ancient writers 

 had explained their preservation in the rocks as the result of 

 great natural catastrophes which had changed the localities of 

 land and water, and brought the swarming denizens of the sea 

 into the middle of continents, burying them there. During the 

 mediaeval Scholasticism no progress was made in the study of 

 fossils. Avicenna (980-1037), the Arabian translator and com- 

 mentator of Aristotle, became imbued with Aristotle's theory of 

 the self-generation of living organisms, and tried to extend it to 

 the case of fossils. Avicenna suggested that fossils had been 

 brought forth in the bowels of the earth by virtue of that 

 creative force (vis plasticd) of nature which had continually 

 striven to produce the organic out of the inorganic, and that 

 fossils were unsuccessful attempts of nature, the form having 

 been produced but no animal life bestowed. 



The famous Albertus Magnus 1 takes the same standpoint 

 more than two hundred years later. He assumes a virtus 

 formativa in the earth as the origin of fossils, although he 

 allows that the remains of plants and animals may be turned to 

 stone in places where agencies of petrefaction are at work. 



With the dawn of the fifteenth century began that long series 

 of disputes about fossils which lasted more than three centuries. 

 The questions under discussion were, whether fossil organisms 

 had taken origin from a vis plastica^ or from living seeds carried 

 in vapours from the sea, or from any living force in the earth 

 itself; whether they might be regarded merely as illusory sports 



1 Albert von Bollstsedt, called Albertus Magnus, was born at Laningen 

 in Swabia in 1193; studied at Padua and Bologna, took Dominican orders 

 in 1222, lectured for several years in the cloister schools of Cologne, 

 Ilildesheim, Freiburg, and Regensburg, and taught in Paris between the 

 years 1245-48. He returned then to preside over the High School at 

 Cologne, and was made Bishop of Regensburg in 1260. This post he 

 resigned after two years, and devoted himself, at Cologne, to his works on 

 philosophical and theological themes until his death in 1280. 



