330 



APPENDIX. 



such as represented in Fig. 354, mounted needles, small 

 scalpels, etc. These, and accessories to 

 the microscope, are described in cata- 

 logues of microscopes. 



333. Material for examination is so 

 extensively abundant that it remains 

 necessary to mention but a few objects 

 most likely to be overlooked. Many 

 isolated cells exhibit a variety of form 

 as ■well as of sculpture or markings. 

 Pollen grains of various plants and 

 spores of different Cryptogams should be 

 examined. Thin longitudinal sections 

 of various stems should also be made; 

 for stellate cells make sections of Kush 

 (Juncus) stems. The cells from the Dah- 

 354 lia root from hard nuts, knots in pears, 



etc., in section, exhibit stratification ; a rather high power 

 must be used in their examination. The rotation of the 

 protoplasm within the cell can be seen in leaves of Vallis- 

 neria, and a few other water plants mounted in water ; the 

 circulation of the protoplasm in the stamen-hairs of the 

 Spiderwort (Tradescantia), in the stinging hairs of Nettle, 

 etc., but with difficulty. The grains of chlorophyll will be 

 easily seen in green tissue, but for beautiful spiral bands, 

 rings and stars, one must examine our numerous fresh-water 

 Algse, or the "green slime" in streams, ponds, etc. For 

 examination of starch grains thin sections of tissue can be 

 made, or the cut surface scraped ; the mass should be 

 mounted in water ; upon the addition of iodine the grains 

 become blue. The stratification is very evident in potato 



Fig. 354. Figures of Forceps. 



