x EXPERIMENTAL PHYSIOLOGY 



i ii. 



PAGE 



31, Muscle held in Muscle-forceps and attached to Simple Lever . 25 



:',-2. Simple Form of Wire Electrodes 26 



83. ELeights of Contraction of a Muscle with Different Strengths of 



Stimuli 27 



34. Marey's Form of Recording Tambour (McKendrick) .... 28 



35. A Second Form of Recording Tambour 29 



3G. A Break Key 30 



37. Plan of the Arrangement of the Apparatus for Recording a Simple 



Twitch 31 



38. Isotonic Twitch of a Hyoglossus Muscle 34 



39. To Illustrate the Meaning of the Curve of Fig. 38 . . . . 35 



40. Simple Twitch of a Gastrocnemius 36 



41. Twitch of a Hyoglossus recorded by a Heavy Lever . . . . 38 



42. The Principle of the Isotonic Method ...... 39 



43. The Principle of the Isometric Method 40 



44. Muscle Attached to an Isometric Lever ...... 40 



45. Three Isometric Twitches with Different Initial Tensions . . 41 



46. Arrangement of Simple Lever for Recording by the Method of 



After-load ............ 43 



47. Twitches Taken under the Principle of After-loading . . . 44 



48. Apparatus for Varying the Temperatures of a Muscle by Immersion 45 



49. Twitches of a Hyoglossus at Different Temperatures ... 46 



50. Twitches of a Gastrocnemius at Different Temperatures . . . 47 



51. Twitches of a Hyoglossus with Different Loads .... 48 



52. Twitches of a Gastrocnemius with Different Loads . . . . 48 



53. Two Twitches given by a Muscle Poisoned with Veratrine . . 50 



54. Work-diagram of a Gastrocnemius for Single Twitches . . . 51 



55. Simple Form of Pendulum Myograph 53 



56. Trigger Key ............ 54 



57. Simple Twitch of Hyoglossus Muscle recorded by the Pendulum 



Myograph ... ......... 55 



58. Arrangement of Upper Part of Drum for applying Two Stimuli to 



a Muscle 57 



59. Effect of Two Successive Stimuli, with Gradually Diminishing 



Intervals, upon a Gastrocnemius 58 



60. Mode of Fitting up a Vibrating Reed 60 



61. Reed arranged to Vibrate in a Horizontal Plane .... 61 



62. The Gradual Production of Tetanus as the Rate of Stimulation 



was Increased 62 



63. The Genesis of Tetanus with Slow Rotation of Recording Surface 64 



64. A Series of Twitches of the Hyoglossus made to Contract every 



half-second to show the Alteration in the Twitch as the Muscle 



becomes Fatigued 68 



65. Prolonged Tetanisation of a Hyoglossus showing Relaxation as 



the Muscle became Fatigued ........ 70 



66. Method of Recording the Thickening of a Muscle as it Contracts 71 



67. Curve I the Shortening, and Curve II the Thickening of a Semi- 



membranosus and Gracilis Preparation 72 



68. Diagram to Illustrate Wave Movement 73 



