Following transection of the nerves innervating the tongue, changes in the lingual mucosa of the cat were observed using a scanning electron microscope. Transection of the lingual nerve induced ipsilaterally marked changes in the lingual mucosa; ulcerous changes occurred within 48hrs after transection of the nerve. In contrast, even 30 days after transection of the hypoglossal nerve, no changes in the lingual mucosa were noted in spite of marked atrophy of the tongue musculature ipsilateral to the lesion. Therefore, the hypoglossal afferents do not seem to be of primary importance for nociception and coordinate movements of the tongue.
An attempt was also made to locate the sensory ganglion of the hypoglossal afferents and the distribution of these fibers in the brain stem by means of the silver impregnation methods. Following intracranial rhizotomy of the hypoglossal nerve, no convincing findings could be obtained indicating termination in the brain stem of fibers running through the hypoglossal roots. Since the afferent fibers in the hypoglossal nerve could reach the brain stem via the roots of the vagus nerve after coursing through the anastomoses between the hypoglossal and vagus nerves, the following experiments were performed. Following intracranial transection of the roots of the vagus nerve, two groups of degenerated fibers were found in the brain stem; fibers in the solitary tract and those in the trigeminal system. The former were distributed to the entire extent of the ipsilateral solitary nucleus, to the commissural nucleus, and to the contralateral solitary nucleus at the level of the commissura infima; the latter were found to terminate in the interpolar subnucleus of the spinal trigeminal nucleus and/or the juxtatrigeminal reticular formation. Following nodosectomy only the components in the solitary tract were degenerated. On the basis of the present and previous findings, it was inferred that at least the majority of the afferent fibers in the hypoglossal nerve reach the brain stem through the vagus roots, and that these fibers, belonging probably to the somatic system, have their ganglion cells in the jugular ganglion and terminate in the spinal trigeminal nucleus and/or the juxtatrigeminal reticular formation.

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In order to study the fine three-dimensional distribution of the synovial vessels, resin casts of the synovial vessels of the dog's knee joint were prepared and observed under the scanning electron microscope.
1. The synovial membrane lining the fibrous capsule has a vascular system of its own, and there are no connections between the synovial vessels and the vessels in the fibrous capsule.
2. Various patterns of the capillary meshes are found according to the difference of the location in the vascular bed of the synovial membrane.
3. At the cartilage border of the synovial membrane, the synovial vessels terminate in the characteristic capillary loops, which are conspicuously more voluminous than ordinary capillaries.
4. In the synovial villi, various vascular patterns such as twisted cords, two-dimensional meshwork and three-dimensional arborization are observed.

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Vertical histological sections of the aorta in rat were easily prepared by supporting it with a piece of macaroni. The procedure is outlined as follows.
The aorta of the rat was dissected out, opened longitudinally and fixed in 10% formalin. After fixation, the aorta was cut into a suitable length. Each segment was rolled spirally with the intimal surface inside. It was then put in a cylindrical piece of boiled macaroni, about 4mm in inside diameter and 7mm in length. The block was sectioned at 8-10μ thickness on a freezing microtome. Every section, when put into water, spontaneously separated from the macaroni and stretched into a long longitudinal section. Frozen sections were routinely stained with Sudan III.
The remainder of the block was subjected to the dehydration process with ethyl alcohol and embedded in paraffin. At the point of pure alcohol dehydration, the piece of macaroni was removed from the hardened tissue. Paraffin sections were submitted to general staining procedures.

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The choroid plexus and the third ventricle wall of the rat brain were observed by scanning electron microscopy.
Macrophages of various shapes known as Kolmer cells were attached to the ependymal surface of the choroid plexus densely covered with microvilli. Some cells possessed numerous fine processes radiating from the centrally located cell body and ending, often with an attenuated web-like tip, among the ependymal microvilli. Others were cells with a few pseudopod-like processes of considerable thickness and length. The latter type was thought to be in locomotion.
The same cells were occasionally also found in the third ventricle wall far from the choroid plexus. The Kolmer cells are thought to be scavengers belonging to the whole ventricular system, though they are gatherd mainly on the choroid plexus.

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The tectorial membrane and otolithic membrane of pigeon inner ear were observed by scanning electron microscopy. Special attention was paid to the possible connection of sensory cells to the membranes.
1. Each hair bundle of the sensory cells of the cochlea was enclosed in a cavity on the under side of the tectorial membrane, the longest hairs being attached directly to the cavity rim. A fine fibrillar structure on the supporting cells of the cochlea was directly connected to the cavity rim of the tectorial membrane.
2. Each sensory hair bundle of the vestibular maculae was surrounded by fine fibrils and projected upwards into a cavity on the lower surface of the otolithic membrane. A connection between the hair tips and the otolithic membrane could not be evidenced, though both elements were supposed to be in contact with each other through the fibrillar structures on the supporting cells of the vestibular maculae.

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The glycogen content in the pineal of the adult female mouse was examined by a semiquantitative histochemical method at different times of the day. As was observed in males in our previous study (KACHI et al., 1971b), it varied diurnally in females in correlation with the daily light and dark periods. In this study, the diurnal variation was considered particularly in relation to the estrous cycle. The pattern of the rhythm appeared to be slightly modified by the estrous cycle, but the difference was not statistically significant between the phases of the estrous cycle.

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The horse pancreas was arterially injected with India ink. After fixation slices were made by hand and cleared in methyl salicylate for microscopic observation.
1. Each islet receives an end branch of the intralobular artery. This artery does not directly supply the acinar tissue, except for issuing rare branches breaking up in smaller, islet-free regions of the pancreas.
2. The arteriole reaches a central point of the islet and abruptly breaks up into swollen capillaries which extend to the periphery of the islet.
3. Thin efferent vessels radiate to communicate, at a certain distance from the islet margin, with the capillary net of the acinar tissue.
4. The horse exocrine pancreas thus receives its blood supply almost entirely, if not exclusively, through the islet. The efferent vessels may functionally be called “portal” though they are capillaries in structure. They convey to the exocrine tissue islet hormones which have recently been learned from our parallel study to be secretagogues to the exocrine pancreas.
5. The vascular route leading the blood from the center to the periphery of the islet in the horse seems purposeful, because glucagon issued from the A cells which are gathered in the islet center in this animal can exert its function as an insulin releaser upon the B cells downstream. In the rabbit which has central B cells and peripheral A cells the vessels are designed to lead blood from the periphery to the center.

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