THE ALG^E. 107 



of the same color as the stem ? Count the leaves in each 

 whorl. Is the number the same ? State what number 

 you find. Measure the lengths of the internodes. Are 

 they all of the same length ? Describe the reproductive 

 organs as they appear under the hand magnifier. Also 

 the apical buds. Draw the entire plant on as large a 

 scale as your notebook allows. 



2. Obtain, if possible, plants of both Chara and Nitella. 

 Examine under the low power. Draw and label an inter- 

 node of each. Cut cross sections of both, holding the 

 specimen between two pieces of pith. Draw and label 

 a cross section of each. Examine any of the internodes 

 of a Nitella plant or one of the youngest leaves of Chara. 

 Are the chlorophyl bodies arranged in any definite way ? 

 Notice the neutral zone that contains no chlorophyl bodies. 

 In what direction does it extend? (See Fig. 60, E.~) 



3. Under both low and high powers examine any of 

 the cells of Nitella or the youngest leaves of Chara for 

 cyclosis or rotation of the protoplasm. Handling the 

 specimen often causes the cyclosis to stop. In that case, 

 place plenty of water under the cover glass and put the 

 slide in a warm place for fifteen or twenty minutes, and 

 the cyclosis will again start. Focus into the cell below 

 the chlorophyl bodies. Draw a cell, showing the neutral 

 line, and indicate the direction of the currents by arrows. 

 From time to time the currents stop and after an interval 

 begin in the opposite direction. The cells of Nitella show 

 cyclosis better than any other known plants. 



4. Keep some Chara or Nitella in alcohol until the 

 chlorophyl has been removed. Mount in alcohol and run 

 iodine under the cover glass. Is starch present ? In 

 another mount of fresh or alcoholic material determine 

 whether the cell walls are composed of normal or fungous 

 cellulose. 



5. Examine fresh young terminal leaves of Chara or 



