J. MARK BALDWIN, Johns Hopkins University 3. I. FRANZ, McLean Hospital, Waverley, Mass. S. J. HOLMÉS, University of Michigan B. F. KINGSBURY, Cornell University ADOLF MEYER, N. Y. State Pathological Inst. C. LLOYD MORGAN, University College, Bristol VOLUME XV DENISON UNIVERSITY, GRANVILLE, OHIO On the Areas of the Axis Cylinder and Medullary Sheath as Cross Sections of the Spinal Nerves of Vertebrates. By HENRY H. DONALDSON and G. W. HOKE. (From the Neurological Laboratory of the University of Chicago.) With one figure. On the Number and Relations of the Ganglion Cells and Medullated Nerve Fibers in the Spinal Nerves of Frogs of Different Ages. Observations on the Spinal Cord of the Emu and its Segmentation. By IRVING HARDESTY. (From the Hearst Anatomical Laboratory of the University of California.) With four figures. The Selection of Random Movements as a Factor in Phototaxis. By S. J. HOLMES. (From the Zoological Laboratory of the University of Mich- Notes on the Development of the Sympathetic Nervous System in the |