LIST OP ILLUSTRATIONS. 



XV 



TRACINGS. 



Tracings of the Muscles. 



Fig. 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 efiects 

 of the poison 35 



Fig, 11. — Gradual coalescence of the shocks produced by electric 



excitations of increasing frequency 46 



Tracings op 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 



Fig. 29. — 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.-r-Leap on two feet at once 131 



Tracings of the Locomotion of the Horse. 



Fig. 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 theswing 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 



