28 



run out towards tlie peripheral protoplasm ; these 

 threads fork repeatedly and suspend the nucleus in 

 the cell sap. The protoplasm also contains numerous 

 drops of oil. 



EEPRODUCTION. 



Two threads lie alongside of each other, the cells 

 of each put out short blunt projections which come 

 into contact, the absorption of the walls at the point 

 of contact forms a narrow canal ; since a number of 

 cells usually conjugate at the same time, the whole 

 forms a ladder-like structure, in which the rungs are 

 represented by the canals. 



After the formation of the conjugating canal the 

 contents of the male cell round themselves off and 

 withdraw entirely from the wall. They then pass 

 into the canal and enter the female cell, which has 

 rounded off (or is in the act of rounding off) its con- 

 tents, both masses come into contact, and after a few 

 minutes coalesce, i.e., the protoplasm fuses, the 

 chlorophyll bands join together, and the two nuclei 

 unite into a single one. The result of this fusion is 

 the formation of a globular or ovoid body, which 

 first contracts and then acquires a thick cell wall. 

 The whole still lies within the much larger mother 

 cell. After a lapse of about twenty-four hours the 

 chlorophyll band is pressed outwards, and the nucleus 

 assumes a central position. 



