400 APPENDIX. 



CHAPTER IV. 



It is especially important that the student become as familiar 

 as possible with protoplasm by a personal study of its structure 

 and physiology. For this purpose the most favorable objects 

 are the Protozoa, which are readily obtained and easily prepared 

 for examination. Directions are given on page 410. Compare 

 with these the protoplasm seen in the cells of the water-plants, 

 as Nitella, Chara (end-cells of leaves, and in the colorless rhi- 

 zoids), and Anacharis ; in the stamen hairs of Tradescantia ; in 

 Spirogyra ; in the cells of the bulb scales of the Onion, etc. 



CHAPTER V. 



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 isolated 

 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. 63, 64). Human blood may be obtained by pricking the 

 finger and mounting the drop in the same manner (Fig. 62). 

 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 pen-holders). 

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



