[Ultrastructural studies of the duck cere with special reference to Grandry and Herbst bodies]

The results of the investigations into the cere of the domestic duck (Anas boscas domestica) and the mallard (Anas platyrhyncha) may be summarized as follows. The parts of ceroma are the epidermis and the corium. The epidermis is a laminated epithelium and the corium consists of fibrous connective tissues. The later one frequently contains mastocytes and pigment cells. There are many blood vessels, Schwann's cells, nerve fibres, Grandry's and Herbst's bodies. The sensory cells of Grandry's bodies are bodies with processes. They are characterized by the round nucleus, dense core vesicles, the small Golgi's complexes, the narrow endoplasmatic ducts and the cytoplasmatic fascicles. In the nerve fibre running between the sensory cells there are plenty of mitochondria but few clear vesicles and neurofilaments. The axolemma, cytolemma, and the empty space lying between these are sharply obvious. In Grandry's bodies with more than one sensory cells the nerve fibre ramifies. In the branches there are no mitochondria. These are replaced by clear vesicles. In Grandry's bodies with one sensory cell the axon ends in a disc growing narrow at its termination. Both of them are full of mitochondria. The terminal disc is characterized by the elliptical bodies and the thickenings of the membrane. Herbst's body consists of three parts. One of these is the inner knob, the other is the inner cavity, the third is the external capsule. The inner knob consists of two series of cells. The number of cells is ten in both rows each. From the cells, 20 to 50 lamina-like processes are originating. The laminar system of every cell is connected with the system of the cell before and behind it, as well as with the laminar system of the other side. In the nerve fibre running between the rows of cells mainly in its terminal part, some groups are formed by mitochondria, the dense-core vesicles, and the elliptical bodies. The inner cavity consists of laminae of different breadths, limited by cavities full of some meshwork. The laminae vary in form and extent. There are among them some ramifying ones, some forms terminating in a point and some of blunt ends. They are characterized by dense and long ribosomeseries, arranged close to one another. The external capsule consists of several parallel laminae, separated from one another by collagenous fibrin fascicles. The laminae are mostly narrow, their cytoplasm is spongoid, they are characterized by egg-shaped cysterns. There is no synaptic organization either in Grandry's or in Herbst's body. The junction between the membrane is to be regarded as a parallel contact in both places.