EARLY HYPOTHESES 5 



outside their too frequent extra-scientific specula- 

 tions, was that they deeply studied fossils and 

 spread the better knowledge of them by exact 

 representations. 



This task of the description and illustration of 

 fossil animals, chiefly the marine shells, was especi- 

 ally the work of the scholars of that eighteenth cent- 

 ury which was the age of systematic zoology. From 

 all quarters they set themselves to gather and collect 

 fossils, to study and describe them by the aid of 

 plates often of great beauty of execution, to which 

 modern palaeontologists are still compelled to 

 have recourse. We may quote the names of 

 Walch, Knorr, and Klein, in Germany ; of Born, 

 in Austria ; of Bourguet and Gessner, in Switzerland ; 

 of Burtin, in Belgium ; of Faujas-Saint-Fonds, in 

 Holland ; of Brander and Solander, in England ; of 

 Soldani, Poli, and Volta, in Italy ; of Guettard and of 

 Bruguieres, in France. 



But the naturalists of that epoch lacked one funda- 

 mental notion, without which the problems relating 

 to the origin and transformations of living forms 

 could not even be enunciated : this was an exact 

 notion of the species and groups that have died 

 out or disappeared. These learned observers had 

 doubtless noticed striking differences between the 

 fossil shells of our countries and the living shells 

 of the neighbouring seas ; but they could not free 

 themselves from the idea that these fossil species 

 would some day be discovered in a living state in 

 distant seas or in the unexplored depths of our 

 oceans. In vain the mathematical philosopher, 

 Robert Hooke, suspected, as early as 1705, the 



