xx LIST OF ILLUSTRATIONS. 



FIG. PA( > E 



275. The curves show alteration in excitability produced by the vapours of 



chloroform, ether, and alcohol (Waller) ..... 536 



276. Effect of faradisation upon the electrical response of nerve (Waller) . 537 



277. Excitatory variations in fresh and stale nerves (Waller) . . . 539 



278. Influence of C0 2 upon the response from "stale" nerve (Waller) . 530 



279. To illustrate internal polarisation in a moist conductor . . .541 



280. Internal polarisation around metallic core of Hermann's model . . 542 



281. „ „ effects in such a model as Hering's . . . 542 



282. Extrapolar polarisation currents on opening polarising current . . 544 



283. Spread of current into extrapolar regions ..... 546 



284. Electrotonic effects of constant current ..... 546 



285. Development of electrotonic currents (du Bois-Reymond) . . 548 



286. Helmholtz's experiment on rate of electrotonic propagation . . 549 

 287-289. Influence of excitation upon electrotonic effect . . 550, 551, 552 



290. After-effects of polarising current ...... 556 



291. Electrical organ of skate. Longitudinal section .... 563 



292. „ ,, „ Diagrammatic view, to show the structure of 



a disc ......... 564 



293. Curve of development of excitatory effects in torpedo organ . . 577 



294. Excitatory effects shown with capillary electrometer . . . 578 



295. Self-excitation of torpedo organ ...... 579 



296. Self-excitation of Malapterurus organ ..... 580 

 297-299. Experiment with „ „ . . . . 580, 581 



300. Evolution of sensory cell (G. Retzius) . . . . .593 



301. Nerve cell from the electric lobe of torpedo (M. Schultze) . . 595 



302. „ cells of Hirudo (Apathy) . . . . . .596 



303. Spinal ganglion cell showing intracellular network of fibrils (C. Golgi) . 597 



304. Nerve cell of annelid (Apathy) . . . . . .597 



305. Diagram of a nerve cell to show the Nissl granules (Cajal) . . 599 



306. Illustrates the "law of axipetal conduction" in motor nerve cells 



(Cajal) ......... 606 



307. Illustrates the supposed lines of conduction in a spinal ganglion cell 



(Cajal) ......... 606 



308. Shows the relative number of the synapses in the visual and auditory 



organs (G. Retzius) . . . . . . .610 



309. Variations of sympathetic nerve distribution .... 630 



310. Diagram of course of a grey ramus . . . . .631 



311. Relations of nerve roots to lumbar and sacral vertebrae . . . 631 



312. Diagram to show variation in nerve origin .... 632 



313. Nerve cell connections of abdominal lymphatic .... 647 



314. Left pelvic plexus of cat . . . . . . . 666 



315. Mechanism of pseudo-reflexes ...... 679 



316. Reflexes and pseudo-reflexes ...... 680 



317. To illustrate certain connections of pre- and post-ganglionic fibres . 681 



318. Experiment of joining the cut vagus and sympathetic in the neck . 691 



319. Method of recording voluntary contraction-curve . . . 707 



320. Tracing of a voluntas contraction of the thumb muscles . . 707 



321. Part of a similar tracing, taken on a faster surface and with the move- 



ments more amplified ....... 708 



322. Vibrations of the outstretched arm holding a weight (W. Griffiths) . 708 



323. Myographic curves from hamstring of monkey (Horsley and Schafer) . 709 



324. „ tracings obtained from stimulation of different parts of the 

 motor path (Horsley and Schafer) . . . . .710 



325. Period of latent excitation on stimulation of the cortex cerebri, and 



