Abstract
Cytophotometric measurements were made of Feulgen stained nuclei of the anterior pituitary cells. A somewhat wider variation in the nuclear deoxyribonucleic acid content of the anterior pituitary cells was observed than had been reported previously in other photometric studies. In comparison to the measurements of the liver nuclei which were used as a reference base, only a few pituitary cells indicated any degree of polyploidy. Three possible explanations of these results are proposed: (1) the variations may have resulted from certain technical inaccuracies of the one wavelength method; (2) this may have been a case of aneuploidy; and (3) these findings may be the result of slight variations in the deoxyribonucleic acid content per nucleus of the different pituitary cells. It is believed that the data supported the deoxyribonucleic acid constancy hypothesis, but the possibility of slight variations in nuclear deoxyribonucleic acid content of the different functional pituitary cells should be considered.