652 JULES MARCOU. 



with such energy that the knowledge obtained was of use to him in his 

 subsequent work. Dr. Germain was in his leisure hours an enthusiastic 

 collector of fossils, and possessed a considerable series of these which he 

 had gathered himself. The interest excited in Marcou's mind by talks 

 with Dr. Germain over his collection, and by tramps in company with 

 him to deposits of organic remains in the strata of the Jura, gradually 

 turned his attention from botany to the more exciting and absorbing 

 pursuit of geology. The astonishingly active and original mind possessed 

 by young Marcou, however, soon got beyond the stage of development 

 reached by his teacher, and he speedily repaid his assistance by greatly 

 increasing the value of his collections through his work in arranging, 

 describing, and naming the specimens. 



In consequence of his rising reputation Marcou was visited by 

 Thurmann, then one of the most prominent of Swiss geologists, and 

 also by Louis Agassiz. Both of these men, especially the latter, had 

 great influence upon his subsequent career. It was largely owing to 

 their encouragement that he offered for publication, in 1845, his first 

 geological work, " Recherches Geologiques sur le Jura Salinois," which 

 was published iu '' Memoires de la Sociote d'Histoire Naturelle de 

 Neuchutel," of which Louis Agassiz was then editor, and subsequently 

 appeared in fuller form in the " Memoires de la Societe Geologique de 

 France," in 1846. The excellence of this work and his high recommen- 

 dations made him the favored candidate for the chair of Professor of 

 Mineralogy at the College of the Sorbonne in Paris in 1846. In 1847 

 he was intrusted with the important work of classifying the collections 

 of fossil shells and corals in the Jardin des Plantes, and is said to have 

 completed this task within a year, and so satisfactorily that he was offered 

 by the great botanist Jussieu, then Director of the Jardin des Plantes, 

 the position of Travelling Geologist, lately made vacant by the assassina- 

 tion of the former incumbent in Peru. This hazardous but much sought 

 for post was exactly suited to his taste, and he accepted it joyfully, 

 choosing for his field of exploration North America, principally on 

 account of the presence of his friend Louis Agassiz in the United States. 



His first expedition after his arrival in May, 1848, was with Agassiz 

 upon the Lake Superior expedition in the same year ; but he left the 

 party at Keeweenaw Point to engage in the study of the copper bearing 

 rocks of that region. His activity in travelling and collecting was at 

 this time prodigious, and the mere list of the places visited and explored 

 would be too long for so limited a notice as can be given here. He 

 sent back to France large collections from many localities, ranging from 



