CRYPTOGAMS 237 



5. Can the nucleus be seen? 



Let a drop of iodine solution flow under the cover glass. 

 Look for starch test. What effect does iodine solution have 

 on the nucleus? From observations on the plants, deter- 

 mine how reproduction is effected. 



Note. This method of reproduction is known as direct cell 

 division. The cell simply cuts itself in two by forming a partition 

 through the center. Each new cell is known as a daughter cell. 

 The original cell is called the mother cell. After cell division the 

 daughter cells remain loosely attached for some time while they 

 proceed to grow. Either one or both of the daughter cells will 

 again divide, thus forming groups of three, four, etc., in clusters- 

 Draw single plants, dividing cells, also any clusters which may be 

 observed. 



201. VAUCHERIA OR GREEN FELT 



This plant is most abundant in muddy pools and ditches, 

 where it forms in masses resembling felt. It is also found 

 growing on damp earth and on moist surfaces of flowerpots. 



Object. To study the structure of vaucheria- 



Method. Examine the pads noting the color, texture, 

 feeling, etc. Under the microscope make out the coarse- 

 ness of the filaments. Do they branch regularly or irregu- 

 larly? Do the filaments show any light relation? If so, 

 what? Is a filament uniform in diameter or does it vary? 

 Is the filament divided into cells by cross partitions? Is 

 the protoplasm uniformly colored? 



Look for rhizoids, or colorless rootlike outgrowths, chloro- 

 plasts, oil globules, nuclei, and a central vacuole. Using 

 iodine solution, determine whether starch is present. 



Look for sex organs, (a) the large oval oogonium con- 

 taining an egg. Look for the pore through which sperms 



