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The paper deals with the structure of the olfactory organ, its accessory parts and the forebrain in the deep-sea fish Aphanopus carbo. On each side of the head only one opening leads to the olfactory chamber. The olfactory folds are arranged in a rosette-like pattern, resembling the 360°-type. Secondary folds on the main folds may serve as an enlargement of the surface of the olfactory epithelium. Most of the surface area of the olfactory folds is covered by the olfactory epithelium, indicating that the receptive area is of optimal extension. The histological structure of the olfactory epithelium is similar to that in other teleost species. The number of olfactory receptors amounts to about 5×10 to 10 for the single organ. Numerous secretory cells of unknown function are located within the olfactory epithelium. The olfactory chamber is enlarged by three accessory sacs: Two ethmoidal sacs and one lacrymal sac (consisting of two parts). These sacs serve as ventilation aparatus which causes a permanent water current within the olfactory chamber and between the olfactory folds. The action of the accessory sacs is induced by the splanchnokinetic. The forebrain of Aphanopus carbo is well developed; its size ranges between that of forebrains in microsmatic and macrosmatic teleost species. A detailed investigation of the forebrain is in preparation. The diagnosis of the different parts of the olfactory apparatus of Aphanopus carbo demonstrates clearly that - in addition to the eye - this sense organ is well developed (relative to that in other teleosts). This fact suggests that Aphanopus carbo is related to a group of teleost species characterized by optical and olfactory orientation mechanisms of high performance. [ABSTRACT FROM AUTHOR]

This 2nd part of our studies shows that the papilla foliata is fully developed in Pan, Cebus, and Macaca; in Prosimians the papilla foliata is well developed in Lemur and Chirogaleus. In Galago crassicaudatus, this papilla is missing. Among 3 individuals of Microcebus, the papilla foliata was differently developed: in 2 cases, the tongue exhibited only 2 on both sides and a very low folia. Taste buds were found in the epithelium of only one side of each folium. In the 3rd case, the folia of the papilla were developed only on one side of the tongue, whereas, on the other side, a typical papilla was missing. Instead of the papilla, the tongue of the same animal exhibited a hillock-like structure; it is a gustatory hillock which exhibited many taste buds. There were 3 gustatory hillocks in all of the specimens of Tupaia glis; they are situated on both sides of the tongue.

This study was carried out on a comprehensive collection of tongues of Pan troglodytes. Material of tongues of Tupaia glis, Microcebus murinus, Chirogaleus major, Lemur catta, Galago crassicaudatus, Cebus apella, and Macaca mulatta were used for comparison of the different stages of the development of the papilla foliata. The tongue of Pan exhibits longitudinal growth correlated with the growth of length of the jaws and individual age. A typical foramen caecum as it occurs in man was gross anatomically not recognizable. Seldom a small circular depression appeared in the midline close to the papilla circumvallata centralis which could be the remnant of the foramen caecum. There is a remarkable accumulation of papillae filiformes and fungiformes at the apex linguae; the same seems to be true for other genera of primates. It is self-explanatory that the accumulation of papillae makes the tip of the tongue a particularly sensitive area; this has been found to be true even in man. One specimen of the prenatal age just before term was studied. It exhibited remarkably elongated, thread-like papillae, their function is unknown as yet. They are no longer present in a newborn specimen of 4 d of age. In the aboral part of the dorsum linguae, a special kind of papillae occur; they are flat lobes which carry moderately elongated, tiny processes at their free margin. The function of these papillae is unknown; taste buds are absent.

The discharge of the material of the Reissner's fibre (RF) and the massa caudalis (MC) into the "meningeal spaces" has until now not been studied in detail and with the aid of the electron-microscope. It was generally assumed that the material of the MC disintegrates in the "meningeal spaces", but the nature and function of those spaces have not been established. The CNS of Ammocoetes ist encompassed by the meninx primitiva, which is the meningeal tissue of the lower vertebrates; the meninx does not differentiate during ontogeny into the pia mater and the arachnoides. In contrast, the meninx primitiva of mammals is the anlage in the ontogenetical sense of the leptomeninges in adult individuals. The results presented in this paper are valid for Ammocoetes only; Petromyzon and Myxine must be studied anew from a perspective which may be the result of our study. Of particular interest would be an anatomical analysis of these caudalmost structures of the CNS (Ampulla caudalis [AC], MC, neuropori, lacunae etc.) in Branchiostoma. The diameter of the RF of Ammocoetes is approximately 1.7 micron; this is not different from the diameter of the RF in adult individuals. In the AC the RF divides into several smaller fibres which eventually disintegrate and form the amorphous MC. In sagittal sections, the fibrillary structure of the RF is distinct. In cross sections the small fibres may appear as globules. The terminal part of the RF is very often coiled. The ependyma of the caudal part of the canalis centralis (CC) ist not remarkable; liquor contacting neurons are frequently found with their dendrites touching the RF. Liquor contacting neurons are never found in the ependyma of the AC. The ependymal cells of the dorsal part of the AC possess neither kinocilia or microvilli. The disappearance of these organelles begins in the dorsal part of the caudalmost segment of the CC. Most surprising is the distribution of the attachment devices which are probably desmosomes. In the ependyma of the caudal part of the spinal cord the attachment devices are typically situated; in the ependyma of the AC these devices are absent. We use the general term "attachment devices" until the nature of these devices has been clearly determined. In the caudalmost part of the spinal cord as well as in the AC, the intercellular spaces between the ependymal cells communicate, forming a 3-dimensional labyrinth. If there are no attachment devices between the proximal parts of the ependymal cells, the intercellular spaces may provide a passageway between the CC and the loose tissue of the meninx primitiva.(ABSTRACT TRUNCATED AT 400 WORDS)

The Plica sublingualis of new world monkeys was studied microscopically. In Ateles there are approximately 1700 taste buds in the epithelium of the Plica sublingualis, they are fewer in number in Alouatta, Lagothrix, Aotus and are absent in Saimiri and Cebus. The taste buds are situated consistently at the tip of the Plica sublingualis and near the orifices of the submandibular and sublingual salivary glands. From this topographical coincidence it is inferred that the function of the taste buds at the Plica sublingualis might permit a comparison between the fresh saliva with the general saliva in the cavum oris along a gradient.

The microscopic anatomy of the sublingua of Tupaia glis was studied comparatively to find out if there is any possible explanation of the origin and the structural characteristics of the sublingual organ in Callicebus. The sublingua of Tupaia is at a primitive stage, but has nothing at all in common with the sublingual organ. The frenal lamella is not remarkable in this species. There are reasons to assume that the sublingual organ is a modified frenal lamella developed only in Callicebus.

Two kinds of secretion are formed in cells of the subcommissural organ (SCO) of Cebus apella. The "light secretion" is found in saccules originating from the endoplasmic reticulum. This secretion is stored in the peripheral portion of the cells and is not involved in formation of Reissner's fiber (RF). In close association with the Golgi complex, electron-dense granules are developed, containing a finely granular substance. These granules accumulate beneath the apical plasmalemma of the cell. Their content is discharged into the third ventricle, where it occurs in the form of a thin layer of secretion. This material appears to constitute the RF at the level of the entrance to the mesencephalic aqueduct.

The macro- and microscopic anatomy of the nasal fossa of Tupaia glis was compared with those of some insectivores. No significant group differences were found as far as the intranasal structures are concerned. Since the number of receptor cells in the olfactory epithelium of Tupaia glis and Talpa europaea is smaller than in the other species studied, a slight reduction of the sense of smell is suggested.

The ependyma of the central canal of the spinal cord of the monkey Cercopithecus nigroviridis was examined by transmission electron microscopy. In the lumbar region and in the filum terminale, many cytoplasmatic protrusions are visible. They are irregular in size and shape and display many microvilli. They are extending into the lumen of the central canal. The basal parts of the ependymocytes occasionally have a very close association with the ependymal blood vessels. The pericapillary space, the pericapillary structures like pericytes and collagen fibrils, and the basal lamina are absent. Opposite branches of the ependymocytes growing together could be observed in the central canal, eventually forming a cytoplasmic unit. Cytoplasmatic extensions of the ependymocytes bridge the lumen of the central canal and melt into each another. Lacunae, such as described by LEONHARDT (1980) in the apical cytoplasm of the ependyma in the rabbit, do also exist in the ependyma coating the central canal of the spinal cord of the monkey Cercopithecus nigroviridis. Some of these lacunae have direct contact to the luminar surface of the central canal, others are separated. Cilia and short microvilli are coating the lacunae. Adjacent ependymal cells form complex interdigitations with each other. Close to their surface on the central canal, there are numerous zonulae adhaerentes. Profiles of the granular and agranular endoplasmatic reticulum are in very close contact to the fine filaments of the zonulae.

In a previous paper, the concept of the terminal organ (TO) of the subcommissural complex was forwarded. Functionally this complex is a neuro (glio-) hemal organ which serves to discharge the Reissner's secretory material into the systemic circulation. The TO is characterized by structural specializations that make feasible the discharge and chemical decomposition of the secretory material stowed in the massa caudalis (MC). The TO is probably not only the ampulla caudalis (AC); it may comprise even parts of the filum terminale next to the AC. The boundary of the TO is uncertain as yet. It cannot be precluded that the AC, which itself varies in shape and size, is just a receptaculum massae caudalis. The material of the MC escapes from the AC either through apertures of the wall of the AC or of the filum terminale (Neuropori caudalis, slit-shaped gaps). It is also likely that the secretory material becomes chemically decomposed in the AC and is intra- (trans-) cellularly discharged. In this connexion, certain ependymal cells may be of significance. These cells exhibit large, tongue-shaped central projections (temporarily developed?) which bear a considerable number of long microvilli. The significance of these cells probably lies in the enlargement of the cell surface bathing in the CSF which contains the MC. These cells are most abundant in the area of the TO; single, isolated cells of the same type occur in other areas of the ependyma of some primates. This would indicate that the TO does not contain special types of cells not found in other parts of the ependyma, but that the TO differs from other ependymal regions in the density of peculiar cell types.

The Reissner's fibre (RF) in the canalis centralis of the spinal cord was studied with the aid of transmission and scanning electron microscope in Tupaia, Cebus, Sarmiri, Macaca, Alouatta, Ateles, Callithrix and Callicebus. The RF of the primates is structurally not different from the corresponding structure of other chordates. The diameter of the RF is slightly increasing in the canalis direction. The increase of the diameter varies between 2 and 5 micron. It is assumed that the increase is brought about by the inclusion of cell debris into the fibre. Material which definitely does not belong to the RF is found in the cerebrospinal fluid (CSF) of the canalis centralis and occasionally it adheres to the surface of the fibre. This material appears either as amorphous flocculent substances, the granulation of which differs in both density and size of the granula or as vesicles. If the material makes contact with the RF, a membrane-like structure may appear which is a condensation restricted to the area of the contact between material of different viscosity and granulation. The origin of this variable material is still not clarified. According to our observations, it is probably sequestrated material from ependymal cells. It is not a secretion as sometimes assumed since the intracellular processes of the synthesis of the secretion have not been observed.

The ependyma lining the central canal of the spinal cord of adult males and females monkey, Callithrix jacchus, was examined by scanning and transmission electron microscopy. The cross section of the lumen of the central canal are round, oval, or triangular. Light and dark ependymal cells, depending on the density of the cytoplasm, were found. The light ependymal cells are fewer than the dark cells. The ependyma cytoplasm contained numerous mitochondria, filamentous structures, one or more well-developed Golgi-complexes, vesicles of the smooth endoplasmic reticulum, ribosomes, lysosomes, multivesicular bodies, profiles of the rough endoplasmic reticulum, large osmophilic bodies, and microtubules. The nuclei of the ependyma cells usually have a simple, regular round or oval shape. They occupy a relatively large portion of the cell volume and lie in the central or mediobasal position. Some of the nuclei show deep invaginations into the karyoplasm. Most of the mitochondria occupy mainly the supranuclear portion of the apical cytoplasm. There are of the crista-typ. Ribosomes occur free in the cytoplasm, but some attached to the profiles of the rough endoplasmic reticulum or being arranged as polysomes. The filamentous structures are generally prominent cytoplasmic components and are distributed at the apical, lateral, or basal region of the ependymocytes. They are grouped into bundles and arranged in parallel arrays. Some of these bundles reach the plasmamembrane at the free lumina of the central canal, others take contact to the filamentous structures of the zonulae adherentes of the junctional complex below the free surface. The granular endoplasmic reticulum shows specializations. There profiles surrounding granular substances and widely distributed granulations in connection with the nuclear envelope. The functional significance of the deposition of these granulations is still unknown. The luminal surface of the ependymocytes bears many microvilli and cilia. The cilia are regularly arranged in cranio-caudal direction. Each cilium has the typical (9 + 2)-subfibres. The intercellular space at the surface of the ependymal layer shows a single zonula adherens or zonulae adherentes in the row. Tight junctions and gap junctions were not found in the material examined. Cell processes of liquor contacting neurons between adjacent ependyma cells, protruding into the lumen of the central canal, could be observed. The termination of these neurons contains accumulations of mitochondria in the central part, large amounts of vesicles, and small dense bodies. They have short microvilli and some stereocilia at the free surface.(ABSTRACT TRUNCATED AT 400 WORDS)

The operative procedure for partially replacing the root with A12O3 ceramic represents a good possibility for preserving teeth in which the pulpa is devitalized. The method used in connection with the well known autoplastic reimplantation not only presents an alternative to the traditional apicoectomy but also provides additional stabilization of the tooth by lengthing the root with cocotostabile and biocompatible A1203 ceramic. The method was tested in humans and monkeys. Argumentation was based on histological examination via light microscopy.

The regio olfactoria of the mole, Talpa europaea, was studied by scanning and transmission electron microscopy. Peculiar structural differentiations, i.e. ovoid-shaped, balloon-like protuberances were found on the surface of the supporting cells. The apical portion of these protuberances contained finely dispersed granular material, whereas in their central part vesicular extensions of the smooth endoplasmic reticulum were observed.