A GENERALIZED PLANT 13 



called a protoplast. Distinguish* the follow- 

 ing parts of a protoplast : 



(3) The prominent green chlorophyll-band, or 

 chromatophore. Describe its form, the 

 number of turns it makes in the cell, and 

 the outline of its margin. Infer its shape 

 in cross-section. How many bands in each 

 cell? If more than one, do they coil in the 

 same direction ? Can you detect free ends of 

 the chromatophore? Are they continuous 

 from cell to cell? The color of the chloro- 

 phyll-band is due to the presence of a green 

 pigment, chlorophyll. 



(4) The denser areas within the chromatophore 

 are regions of starch-formation. In the 

 center of this area is the starch-forming 

 body, or pyrenoid. Surrounding the pyre- 

 noid are starch grains. 



(5) Make a detailed drawing, 10 mm. wide and 

 15 mm. long, showing the details of struc- 

 ture of a portion of the chlorophyll-band, 

 as seen under high power. Indicate on the 

 drawing the names of all parts shown. 



(6) At or near the center of the cell find a dense, 

 colorless body, the nucleus, surrounded by 

 a less dense layer of colorless cytoplasm. 

 Describe the shape of the nucleus. From 

 the layer of cytoplasm trace 



(7) Delicate cytoplasmic strands, extending to 

 the pyrenoids, and to 



(8) The lining layer of cytoplasm. This layer 

 (sometimes called "primordial utricle") is 

 in intimate contact with the entire inner 

 surface of the cell-wall, and is difficult to 



