B. CELL CONTENTS. 



The several illustrations following, represent the secondary 

 products of the cell as distinguished from active protoplasm and 

 its immediate derivaties, the chlorophyll body. The secondary 

 products are found chiefly in the fundamental or cellular tissue, the 

 characteristics of which will be observed. The solid forms of these 

 products will be studied as follows: 



1. Starch Grains. 



2. Crystals. 



3. Protein granules. 



4. Crystalloids. 



5. Aleurone grains. 



Illustration First: Showing PARENCHYMA CELLS with STARCH. 

 The TUBER of the POTATO. (Solatium tuberoswn.) (Fig. 11.) 



PREPARATION: Cut a fresh surface on a tuber, make several 

 thin sections from 2-3 m. m. in breadth and as thin as possible. 

 Mount in water. 



OBSERVE: 1. Form of the parenchyma cells of the tuber. 



2. Ovoid or pyriform starch grains, of various sizes, lying in 

 and about the cells. 



3. Structure of grains; some plainly showing a hiltim, 

 around which appear rings more or less eccentric. The rings are 

 layers of greater or less density. 



4. Measure some of the larger grains. 



5. Sun a drop of weak iodine under the cover and note the 

 blue color resulting in the grain, the characteristic reaction for 

 starch. Sketch a tuber cell with contained starch grains. Vines' 



