The courses of the cutaneous branches arising from the dorsal rami of the cervical and the upper thoracic nerves were examined on 61 sides in 31 human adults, and their positional relations to the semispinalis cervicis muscle were particularly noted. Absence of the cutaneous branch from the dorsal rami of the lower cervical nerves was observed in 60 of the 61 cases; and in the one remaining case, all the cervical nerves except C1 gave off a cutaneous branch. A difference in course of the cutaneous branches was clearly observed between those from the upper cervical and the upper thoracic segments. That is, those of the former passed superficial to the semispinalis cervicis, whereas those of the latter were situated deep to it. The absence of cutaneous branches of the lower cervical segments could be classified into two types: continuous absence and alternate absence. In the former, which was observed in 53 cases (87%), cutaneous branches were absent in continuous segments. In the latter, which was observed in 7 cases (11%), they were absent in alternate segments. Dermatome problems are discussed on the basis of the present results. Keegan-Garrett's chart could be supported in the one exceptional case only.

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We demonstrated a new differentiation type of chief cell in the cat gastric gland. 1. Numerous PAS-positive cells were distributed not only in the glandular body but also in the glandular base. 2. These cells, namely immature chief cells, contained a large number of claret-colored fine pepsinogen granules. 3. Immature chief cells did not exist in the glandular base of man and many other types of animals. 4. The PAS-positive cells in the glandular base gradually decreased in PAS-positive substance and changed into PAS-negative cells with a reticulate framework. These mature chief cells contained numerous dark blue coarse pepsinogen granules. 5. The mature chief cells reacted moderately to AB (pH 2.5), and weakly to AB (pH 0.5), while staining with PAS-AB (pH 2.5) produced a moderate to strong color reaction of AB. Such reactions were characteristic to these cells and could not be found in man or many other types of animals studied. 6. PAS-positive cells i. e. the immature chief cells, reacted strongly to AB (pH 2.5), and moderately to AB (pH 0.5), while staining with PAS-AB (pH 2.5) produced a violet color. 7. The above-mentioned reactions were the same in mucous neck cells with mean undifferentiated characteristics. Such cells do not exist in the glandular base of man and many other types of animals. 8. The glandular base is generally occupied only by mature chief cells, though a large number of undifferentiated cells or immature chief cells were distributed in the same area of the cat. 9. Strongly PAS-positive cells were also distributed in the glandular body and base of the swine. These cells in the glandular base had differentiated to mature chief cells. However, we presume that the strongly PAS-positive cells in the swine originate from germinal cells in the top region of the glandular neck, while the precursors of PAS-positive cells (immature chief cells) in the cat are mucous neck cells.

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The blood vascular architecture in three-paired external gills of salamander tadpoles, Hynobius dunni Tago, was demonstrated with special reference to metamorphosis by scanning electron microscopy of vascular corrosion casts. In the fully developed gill, each of the three-paired afferent branchial arteries gave off secondary afferent filament arterioles. The afferent filament arteriole drained toward the efferent filament arteriole, forming the loop at the posterior extremity of the gill filament. The branched capillaries from the afferent filament arteriole formed two plates of respiratory capillary networks with irregular honeycomb-shaped meshes. In addition, there were non-respiratory shunts as bypass of the blood circulation between the afferent and efferent branchial arteries without branching filament arterioles. Furthermore, the deep venous plexus and subepithelial capillary plexus were seen around each efferent branchial artery. The filament central venule in the central part of the filament merged into the venous plexus. Nutritive capillaries branched from efferent branchial arteries also drained toward the venous plexus. Such general vascular architecture is simpler than that of the fish. During metamorphosis, the pattern of the vascular distribution, especially filament net capillaries became irregular, and then markedly tortuous or convoluted blood vessels occurred in the absorbing gill. At the metamorphic climax, the capillary network practically disappeared in the remnant of the gill but the bypass shunt as a non-respiratory artery remained almost unchanged.

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In an attempt to elucidate the functions of three types of filiform papillae in the rat's tongue, corrosive resin casts of the microvessels in the filiform papillae were observed under the scanning electron microscope. The filiform papillae were also examined by light and transmission electron microscopy. The three dimensional architecture of the microvessel loops in the small conical filiform papillae was relatively simple with limited divergence and anastomosis in the papillae, whereas that in the large conical filiform papillae formed a complex network which resulted from repeated divergence and anastomosis. The microvessels in the thready filiform papillae branched several times in the primary papillae and then formed a hairpin-like loop in each of the secondary papillae. Under the light and transmission electron microscope, the small and large conical filiform papillae revealed remarkably similar tissue architectures, with the exception of their sizes. However, these two types of filiform papillae were arranged in quite opposite directions. In the large conical filiform papillae, the epithelium on the anterior side of the papillae lacked a granular layer, whereas the epithelium on the posterior side contained a well-developed granular layer. Based on these findings, we presume that the functions of the three type of filiform papillae are as follows. That of the small conical filiform papillae is to take food efficiently into the oral cavity. That of the large conical filiform papillae is to grind further the food which has been crushed with the teeth in coordination with the palate. The thready filiform papillae might function as a heat-releasing organ and be involved in the control of body temperature.

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The myelinated perikaryon was found in some of the retinal ganglion cells of parrakeet. The cells were covered with a compact myelin composed of 1-10 lamellae. The myelin of the ganglion cells seems to be formed by Muller cell.

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A case of complete ureteropelvic duplication is reported. In this case, two ureters, i. e. a ureter from the superior renal pelvis and one from the inferior renal pelvis, began within the sinus of the left kidney. This case was in agreement with the "Weigert-Meyer Law".

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