LIST OF WOODCUTS. 



FIQ. PAGIt 



1. Amcebre 6 



2. White Blood-Corpuscles from a Guinea-Pig .... 7 

 MI. Ciliate Cells situated with the other Cells on a Mem- 

 brane . . . . . . . . . .10 



3&. A single Ciliate Cell, greatly magnified, of somewhat 



abnormal form 10 



4. Striated Muscle-Fibres 13 



5. The Double-headed Calf-Muscle (. gaetrocncmi-us) with 



its Tendons 17 



6. The Bones of the Arm . .... 19 



7. Du Bois-Reyinond's Apparatus for studying the Elastic 



Extension in Muscle . . . . . . . 25 



8. The Simple Myograph ... 26 



9. Du Bois-Reymond's Muscle-Telegraph 29 



10. Induction Coil 31 



11. Electric Wheel 33 



12. Wagner's Hammer 34 



13. Du Bois-Reymond's Sliding Inductive Apparatus . 35 



14. Du Bois-Reymond's Tetanising Key 36 



15. Heights of Elevation with different Weights . . . . 38 



16. The Changes in Elasticity during Contraction ... 48 



17. Helmholtz's Myograph 52 



18. The Curve of Pulsation of a Muscle . .... 56 



19. Measurement of small Angles of Deflection with Mirror 



and Lens 57 



20. Apparatus for measuring the Duration of Muscle-Contrac- 



tion GO 



21. End of the Lever of the Time-determining Apparatus with 



Capsule of Quicksilver 61 



22. Diagram of Experiment for measuring Electric Time . 62 



23. Diagram of the Flexor Appara 1 us of the Forearm . . 68 



24. Dynamometer .69 



