PHOSPHATASES IN NORMAL AND REORGANIZING STENTORS

¹ Arnold Biological Laboratory, Brown University, Providence, Rhode Island

Phosphatase activity is studied in Stentor coeruleus by means of histochemical methods. "Alkaline" procedures are negative. Acid phosphatase may be consistently demonstrated in normal Stentors around the macronuclei, in the basal granules of the membranelles and the body cilia, in the endoplasmic fat vacuoles, and around the gastrioles. During starvation a gradual decrease in intensity and distribution of enzyme activity is observed, while in regeneration, physiological reorganization, and in vegetative division, activity remains unaltered in comparison to the normal animal. Presumptive evidence is obtained indicating that acid phosphatase in the basal granules is not primarily a factor in ciliary differentiation.