Histogenesis of the argentophile cells of the proventriculus and gizzard of the chicken

Special granulated cells, frequently ref erred to as basallygranulated cells although the granules may not always be restricted to the basal portion of the cell, are present in the digestive tract, of all vertebrates that have been studied. They are commonly most numerous in the intestinal epithelium, may occur in considerable numbers in the stomach but are usually lacking in the esophagus, especially of birds and mammals. Cells of this general class may be demonstrated by a variety of histological and histochemical methods but there is some question whether o r not they constitute a single class of cell since many methods employed are not entirely specific. It is generally accepted that many of these cells exhibit suecessive stages of maturation in which the constitution of the granules undergoes progressive chemical or physicochemical modification. A more extreme view is that there may be 2 distinct classes of cells. The Rlasson-Hamper1 silver method, utilizing an ammoniacal bath without a reducing agent, blackens certain granules selectively. This is the argentaffin reaction, and a positive reaction of this kind in the granules is correlated with positive chromaffin and diazo reactions and yellow fluorescence under ultraviolet illumination. For ordinary purposes of