Scanning and transmission electron microscopic observations have been made in the terminal region of the vas deferens of the cat, with emphasis on the occurrence of spermiophagy. The present study has revealed that epithelial cells as well as luminal macrophages are extensively and actively involved in phagocytosis of spermatozoa. The mechanism of the spermiophagy is discussed, in relation to a possible role of the epithelial cells, as one function of the vas deferens.

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Summary.The adult cat oviduct was viewed by SEM and TEM as spermatozoa of the same species and inert latex beads were injected into its lumen.The present study demonstrates that nonciliated epithelial cells in extensive areas of the oviduct as well as luminal macrophages are capable of actively taking up both the spermatozoa and the latex beads in the manner of phagocytosis.The epithelial cells are thus able to eliminate foreign bodies including degenerating spermatozoa in order to scavenge the lumen, though the cellular mechanisms involved in their phagocytosic activity remain to be elucidated.

Summary : The relationships between sensory nerve fibers and odontoblast processes in the human dental pulp were investigated primarily with the scanning electron microscope.The nerve fibers in the pulpodentinal border zone ramified from the nerve plexus which formed a dense interlacing network beneath the odontoblast layer. They run along the processes of odontoblasts in the predentin and dentin.In the odontoblast layer, a few nerve fibers were observed along one odontoblast body and some of them had branches which extended to the neighboring body. Axonal varicosities of various sizes were observed not only in the odontoblast layer but also in the predentin and dentin. The diameters of the nerve fibers and varicosities were smaller in the deeper regions of the dentin. The axoplasm of the varicosities contained many mitochondria, vesicles which were 30-150 nm in diameter and glycogen granules. The number of varicosities in the deeper portion of the dentin was greater but the diameters of the varicosities were smaller about 2 gym. Thus small beaded varicosities were frequently seen in close apposition to the odontoblast processes in the dentin.The function of the varicosities for sensory perception in the dentin is discussed.