24 GREEN' SLIME. 



1. The individual cells; either single or associated in 

 families. 



2. The size of the cells ; some small, some several times 

 larger. 



3. The shape ; when free and when in families. 



4. The cell contents ; more or less granular, and always 

 green from the presence of chlorophyll. 



5. The colorless cell- wall surrounding each cell. 

 Press upon the cover-glass with a back and forth move- 

 ment, and the walls to many of the cells and cell-families 

 will be ruptured and their contents ejected, when the 

 wall can be easily studied. 



Stain with iodine and notice 



6. The brownish-yellow color given the contents of the 

 cell, showing the presence of protoplasm. 



Stain a freshly mounted specimen with dilute chlor- 

 iodide of zinc, and after an hour or two 4 notice 



7. The two to several closely packed bodies of definite 

 outline, usually overlapping, forming the green part 

 of the cell, the chlorophyll bodies, best seen in the 

 largest, single, round cells. 5 



8. The small round body nearly in the center of the cell, 

 or in recently divided cells near the partition wall, the 

 nucleus. 6 



9. Occasionally a clear space between the chlorophyll 

 bodies and the cell wall, occupied by \hzprotoplasm. 



10. Draw a few cells showing chlorophyll bodies and 

 nuclei. 



4 If the cells are properly stained they will usually remain green, but of a 

 brighter and more bluish hue. 



5 There is danger of mistaking delicate partition walls of young cells, 

 which the reagent has thickened and made visible, for the boundaries of 

 the chlorophyll bodies. 



6 Under higher power yet a central dot to the nucleus, the nucleolus, 

 may be detected. 



