22 THE BIOLOGY OF THE CELL 



the cell contain ? Are the cells very abundant in 

 the saliva ? Do they in their structure resemble 

 any of the Protozoa % 

 Eun a drop of magenta under the cover-glass, and 

 note the changes in the cells. Prepare another specie 

 men, and treat with dilute iodine. Test a third prepa- 

 ration with one per cent, acetic acid ; a fourth with one 

 per cent, acetic acid carmine. In each case note the ef- 

 fect upon the entire cell and upon each of its parts. Of 

 what use are these reagents and stains ? 



Make drawings illustrating the structure of the sa- 

 liva cell. 



PHTSIOLOGT 



a. Motion. — Prepare another specimen as first directed, 

 and place it upon the warm -stage, being very 

 careful to keep the stage at the proper tempera- 

 ture — *'. e., that of the body. 



Does the cell have the power of voluntary 

 movement ? Does it have cilia ? Note the pe- 

 culiar dancing motion or Brownian movement of 

 the contained particles. Do you find any cells 

 in the process of division ? 



h. Nut/rit/ion. — Grind a little indigo or carmine in water, 

 and run a drop under the cover -glass. "Watch 

 the cells to see whether or not they ingest the 

 particles. Note the Brownian movement of the 

 particles of indigo or carmine. Do you think 

 that this motion indicates that the particles are 

 alive ? 

 Make drawings illustrating any changes noticed in 



cells examined upon the warm-stage. 



