1846.] IN THE "GALERIE DE ZOOLOGIE: 267 



From the time of his first establishment at Neuchatel, 

 Agassiz had taken great interest in the echinoderms, 

 publishing, from 1833 to 1845, numerous and most 

 important memoirs on the subject. His stay at Paris 

 was an opportunity long looked for, and he seized 

 upon it with his usual enthusiasm. All the public and 

 private collections were at his complete disposal. The 

 Jardin des Plantes, with its vast wealth, known and 

 unknown, was thrown open to him. The old gallery 

 of zoology, just opposite the " Pitie Hospital' had its 

 best room barricaded ; and drawers filled with speci- 

 mens, barrels of all shapes, containing collections of 

 marine animals from all parts of the world, and never 

 opened until now, were brought from cellars and gar- 

 rets, and arranged in front of the usual collection of 

 echinoderms exhibited to the public. Agassiz placed 

 the specimens on long tables ; and there, with the help 

 of his friend Valenciennes, professor of conchology, 

 and his assistant, Louis Rousseau, - - a brother of the 

 great landscape painter, Theodore Rousseau,- -he began 

 classification and determination, dictating to his secre- 

 tary, Desor, the descriptions of families, genera, and 

 species. Sometimes his enthusiasm was raised to per- 

 fect rapture, when some new species or a new genus 

 was found in one of the barrels brought up from the 

 Pacific Ocean by exploring expeditions of the end of 

 the last or the beginning of this century. It was 

 interesting and also amusing to see him with a sea- 

 urchin in one hand, and a lens in the other, analyzing 

 each organ and each part of the animal, with that accu- 

 racy of description for which he was justly celebrated ; 



