LABORATORY AND FIELD EXERCISES 



the shape and color of the chromosomes ? Are 

 they all of the same form and color ? Have they 

 any definite position in the nucleus with refer- 

 ence to the nuclear membrane ? 



(2) Spindle. Do you see any evidence of a forming 



spindle at the two ends, or poles, of the nucleus 

 you are studying ? See the text on the origin 

 and structure of the spindle. 



(3) Cytoplasm. Is the cytoplasm of the same struc- 



ture around the nuclear membrane and at the 

 periphery of the cell ? If any difference is noted, 

 in what does the difference apparently consist ? 

 What is the apparent structure of the cytoplasm ? 



(4) Draw a cell greatly magnified (1 or 2 inches in 



length) to bring out the above points. Draw the 

 chromosomes very accurately. 

 b. Metaphase. 



(1) The nucleus and the nuclear membrane. Do you 



find any definite nuclear membrane and nuclear 

 cavity in the metaphase stage ? What changes 

 have taken place in the nuclear membrane since 

 prophase ? 



(2) The chromosomes. Has their form changed since 



prophase ? Have the chromosomes a definite ar- 

 rangement in metaphase ? How are they appar- 

 ently supported in their position ? If you could 

 see a polar view of the chromosomes in meta- 

 phase, what arrangement would they appear to 

 have ? Indicate this position of the chromosomes 

 in an outline drawing. 



(3) The spindle. Observe the spindle carefully with a 



. high power. What is its apparent structure? its 

 form? Can you determine any definite relation 



