42 LIVING MATTER OR PROTOPLASM. 



But it would be absurd to suppose this identity absolute, for if it 

 were so, plants and animals would also be identical ; and fur- 

 thermore, the protoplasm of every species of plant and animal 

 must differ more or less from the protoplasm of every other spe- 

 cies. What is meant is, that the differences between the many 

 kinds of protoplasm are secondary to the fundamental resem- 

 blances which underlie them. 



PRACTICAL STUDY. 

 A. Protoplasm. 



1. Take a long cell of Nltella or Vaucheria, lay it upon a 

 slide, cut off one end, and with the back or handle of a scalpel 

 press the cell gently from the other end so as to drive out the 

 contents. Observe with the naked eye the small drop of viscid 

 fluid, lift some of it upon a needle-point to test its viscidity, then 

 cover, and examine with the highest power at hand. The color- 

 less portions of the whole mass are often called protoplasm, but 

 only the clearest portion, tilled with innumerable fine black par- 

 ticles, is really entitled to the name. (If no long-celled plant is 

 at hand, any soft cells, e.g., those of Spirogyra or yeast, may be 

 crushed by pressure upon the cover-glass, and will answer.) 



2. Add iodine, and note the effects. 



3. Examine the protoplasm in cells of cartilage, in sections of 

 the cotyledons of sprouting beans, in sections of the leaf-stalks of 

 young leaves of geranium (Pelargonium], or in other objects fur- 

 nished by the demonstrator, and report your results. 



4. Study the movements of protoplasm in vegetal cells e.g., 

 Chara, Nitella, or Tradescantia and in some animal cell e.g., 

 Amceba, Gregarina or colorless blood-corpuscles or in other ob- 

 jects, and compare p. 20. 



5. Snip off with fine scissors a bit of the gill of an oyster or a 

 clam, mount it in normal fluid or in the blood of the animal, 

 and examine with a high power. Find a spot where the cilia 

 are moving slowly, and observe the ciliary action. Sketch. 



6. In the same preparation employed in (5), or in a fresh one, 

 note the effects of carmine finely rubbed up in a mortar with 

 water and run under the cover-glass. Compare the result of this 



