PLATE 16 



Fig. 18. Division stage. Macronucleus at maximum contraction. New anal 

 cirri fibers forming. Frontal cirri not shown. Alcoholic haematin stain. X 535. 



Fig. 19. Early constriction. Mallory's connective tissue stain. X 535. 



Fig. 20. Later constriction. Mallory's connective tissue stain. X 535. 



Fig. 21. Division almost complete. New motorium forming in posterior 

 daughter. Mallory's connective tissue stain. X 535. 



[396] 



