Page:Popular Science Monthly Volume 77.djvu/223

Rh is brought about by the stimulation of the electric nerve, which in turn acts upon very minute electric rods that release the electricity.

Above the aquarium is the library. In the north room are found in complete series all the most important biological journals. In the south room are the separate volumes, monographs and authors' reprints. The current numbers of journals and the latest publications from all parts of the world are found upon central tables. The classification and arrangement of the books is simple and the card-catalogue complete. Each worker is given cards bearing his special number in the general list and he inserts one of these cards in the place of the book desired. Dr. Schoebel, the librarian, is always ready with assistance in case of need. On the walls are notable frescoes by Hans v. Marées, one of the group of four especial friends of Dohrn when, in 1871, he was Privatdozent at the University of Jena. In the fresco on the east wall, Dohrn and these four friends, the biologist Kleinenberg, Charles Grant, the author of "Tales of Naples and the Camorra," the artist himself and the sculptor Hildebrand, are represented as grouped about a table at the ruins of the Palazzo di Donn' Anna on the Posilipo. In two other scenes, first Neapolitan fishermen are carrying the net from the shore and launching their boat and then four stalwart fishermen are rowing, standing in their characteristic manner and bending forward with each push upon the oar. On the south wall three ages of man are represented