LIST OF ILLUSTRATIONS. XV 



PAGE 



TRACINGS. 

 TRACINGS OF THE MUSCLES. 



4. Character of the shock according to the degree of fatigue 



of the muscle . . . . . . . 34 



FIG. 5. Successive transformations of the shock of a muscle be- 

 coming gradually poisoned by veratrine. Underneath 

 and on the left of the figure are shown the first effects 

 of the poison ........ 35 



FIG, 11. Gradual coalescence of the shocks produced by electric 



excitations of increasing frequency 46 



TRACINGS OF HUMAN LOCOMOTION. 



FIG. 20. Tracings of the impact and the pressure of the two feet in 



our ordinary walk . . . . . . .114 



FIG. 22. Tracings of the oscillations of the body during walking . 117 

 FIG. 25. Tracing of the impact and rise of the right foot, furnished 

 by a lever subjected at the same time to 10 vibrations 

 per second ......... 121 



Fro. 20. Tracing produced by walking upstairs .... 128 



FIG. 30. Tracing produced by running (in man) . . . . 128 



FIG. 31. Man galloping (right foot foremost). Step-curves and re- 

 actions. There is an encroachment of one curve over the 

 other, and then a suspension of the body . . . 131 

 FIG. 33. Series of hops on the right foot. The duration of the 

 time of suspension remains evidently constant, even 

 when that of the pressure of the foot varies . . . 132 

 FIG. 32. Leap on two feet at once 131 



TRACINGS OF THE LOCOMOTION OF THE HORSS. 



FlG. 50. Tracing and notation of the walking pace, with equal 



pressures of the feet, both diagonally and laterally . . 160 



FIG. 45. Tracing and notation of the trot 153 



FIG. 55. Tracing and notation of the gallop in three-time . . . 165 



TRACINGS OF THE FLIGHT OF INSECTS. 



FIG. 70. Showing the frequency of the strokes of the wing of a 



drone-fly and a bee ....... 183 



FIG. 72. Graphic tracing of the middle portion of the course of a 



bee's wing 189 



