SPIROGYRA. 



34. Vegetative Stage. Draw a piece of a filament under the low power, showing : 

 cells, arranged end to end ; cell- walls ; spiral chloroplasts. Then draw one cell under 

 the high power, showing : cell-wall ; protoplasm ; chloroplasts containing pyrenoids ; 

 nucleus with protoplasmic strands crossing large vacuole, 



35. Growth. Find a cell in which the nucleus has divided and draw it under the high 

 power, showing the commencement of new cell-wall. 



36. Sexual Reproduction. Examine the supplied material under the low power 

 and find successive stages in conjugation. Make drawings to show : lateral outgrowths ; 

 conjugation tubes ; passage of cell contents ; zygotes. 



