1 70 HOW TO WORK 



2. SECONDARY MOVEMENTS the consequence of vital move- 

 ments, or of other phenomena, affecting matter which is not in a 

 living state : 



a. Ciliary Movements. Probably due to alterations in the quantity 



of fluid within the cell, the changes in the proportion of fluid 

 being brought about by the action of the living or germinal 

 matter of the cell. 



b. Muscular Movements. Due to a disturbance (electrical or 



otherwise) in the neighbourhood of a contractile tissue that 

 is, a structure so disposed that its constituent particles are 

 susceptible of certain temporary alterations in position, which 

 alterations take place in certain definite directions only. 

 c. Molecular Movements. Which affect all insoluble particles, 

 non-living as well as living, in a very minute state when sus- 

 pended in a fluid -not viscid. 



-d. Movements of Solid Particles susper.ded in Fluid in Cells, caused 

 by Currents in the Fluid, as the pigmentary matter in the 

 pigment cells of the frog. Due to the motion of the fluid as 

 it passes into, or out of, the cell, through its permeable wall ; 

 'this movement being dependent upon changes taking place 

 external to the cell. 



262. Of the Primary or Vital Movements occurring In Living 

 Beings. This kind of motion is peculiar to matter in the living 

 state, and is not known to occur in any matter which has not been 

 derived from matter in a living state. The movements cannot be 

 imitated. They cease when death occurs, and having once ceased, 

 they cannot be caused to reappear in the same particles of matter. 

 Excellent examples of vital movements are presented in the common 

 amcebce and many other low forms of life, in the white blood corpuscles, 

 in mucus and pus corpuscles, and less distinctly in the germinal matter 

 (nuclei) of many tissues of the higher animals. 



Amcebce, can always be obtained by placing a small fragment of 

 animal matter in a wine-glass full 'of water and leaving it in a light 

 part of the room for a few days. I have found it convenient to 

 introduce a few filaments of the best cotton wool into the water. 

 The amoebae collect amongst the fibres which protect them from 

 being crushed by the pressure of the thin glass when removed to 

 the glass slide. An imperfect idea may be formed of the changes 

 taking place in the form of the most minute amoebae by reference to 

 fig. XL, pi. .254. 



Mucus Corpuscles in the mucus upon the surface of the mucous 

 membrane of the air-passages, white blood corpuscles, and pus 

 corpuscles exhibit similar movements, fig. 256. Changes in form 



