ENDOCRINE (APUD) CELLS IN THE OVIDUCT OF THE SHEEP

APUD cells in the oviduct of the sheep at standing estrus were localized as paraneurons in the lamina propria sandwiched between this structure and the tunica muscularis by the method of masked metachromasia to toluidine blue after hot mineral acid hydrolysis. These were also confirmed by lead haematoxylin stain and argyrophilia. The oviduct was serialized into 66 zones. Cells were absent in the first and last 2 zones, and most parts of the isthmus. There was however abundant number of APUD cells in the ampulla which were fusiform shaped and were about $5{\mu}m$ width and also in the juncture, where the cells were of a smaller width ($3{\mu}m$) and were quite numerous reaching 180-200 in some zones. It is concluded that peptide secreting cells are numerous in the oviduct and that this may qualify the oviduct as an endocrine organ.