XII 



MOVEMENT 



Mechanics as the science of motion (kinematics and phoron- 

 omism) — Chemistry of vital movement — Active and 

 passive movements-'^Undulatory movement^Mechanism 

 of imbibition-^Autonomous and reflex movements — Will 

 and willing — Mixed movements — Movements of growth — 

 Direction of the vital movement — Direction of the crystal- 

 lizing force — Direction of cosmic motion^Movements of 

 protistS'— Amoeboid, myophenous, hydrostatic, secretory, 

 vibratory movements: cilia and lashes^Movements of 

 histona, metaphyta, and metazoa — Locomotion of tissue 

 animals: ciliary motion and muscular movements — Muscles 

 of the skin — Active and passive organs of movement — ■ 

 Radiata, articulata, vertebrata, mammalia — Human move- 

 ments. 



ALL things in the world are in perpetual motion. 

 L The universe is a perpetuum mobile. There is no 

 real rest anywhere ; it is always only apparent or relative. 

 Heat itself, which constantly changes, is merely motion. 

 In the eternal play of cosmic bodies countless suns and 

 planets rush hither and thither in infinite space. In 

 every chemical composition and decomposition the 

 atoms, or smallest particles of matter, are in motion, 

 and so are the molecules they compose. The incessant 

 metabolism of the living substance is associated with a 

 constant movement of its particles, with the building 

 up and decay of plasma-molecules. But here we must 

 disregard all these elementary kinds of movement, and 

 be content with a brief consideration of those forms of 



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