486 APPENDIX 



water plants, as Nitella, Chara (end cells of leaves, and in the 

 colorless rhizoids), and Anacharis; in the stamen hairs of 

 Tradescantia ; in Spirogyra ; in the cells of the bulb scales of 

 the onion, etc. 



CHAFFER VIII 



In studying protoplasm, many kinds of cell will probably be 

 seen. Those mentioned are especially large, and in them the 

 protoplasm is likely to be in quite active motion. To illustrate 

 cell structure use not only the lowest organisms, but also iso- 

 lated cells from higher animals and plants for example, blood 

 cells from the frog and from the human body. Frog's blood 

 may be obtained by killing the animal in a box in which has 

 been placed a small wad of cotton saturated with chloroform; 

 as soon as the frog is dead cut into its skin to make the blood 

 flow, then on a glass slide mix a drop of the blood with a drop 

 of a .75 per cent solution of salt in water, put on a cover glass, 

 and examine under a one- fourth to one-sixth inch objective 

 (Figs. 260, 261). Human blood maybe obtained by pricking the 

 finger and mounting the drop in the same manner (Fig. 259). 

 Study also the cells seen in a drop of saliva. Some of these, 

 the salivary corpuscles, are small and usually spherical in shape ; 

 others, the epithelium cells, come mainly from the lining mem- 

 brane of the mouth, are polygonal in outline, have a large nu- 

 cleus, and are frequently found in groups consisting of several 

 cells. Ciliated cells are easily obtained by placing in a drop of 

 water on a slide a small portion of the gill of a live oyster or 

 clam, and picking it to pieces with dissecting needles (ordinary 

 cambric needles fixed by the eye end into wooden penholders) . 

 Examine under a one-fourth or one-fifth inch objective. Some 

 of the pieces will probably be seen swimming about by means of 

 their cilia (Fig. 199, ). With these animal cells compare such 

 vegetable cells as pollen grains, spores of fungi, the cells com- 

 posing the bodies of some of the fresh-water algae, etc. 



As the satisfactory preparation of the tissues requires skill 

 obtained only by long training in manipulation and in the use 

 of hardening fluids, stains, etc., in many cases it will be prefer- 



