The morphometrical study of minor calices was performed using rubber cast preparations of 100 kidneys obtained from 75 Japanese adult cadavers. The results were as follows;
1) Numbers of minor calices of each kidney are independent of the factors such as sex, laterality, age and kidney size. Each kidney has 8.58± 1.85 minor calices with sufficiently good accuracy.
2) Neck parts of the minor calices were classified into the following 3 types; neck type 67.5%, half-neck type 23.5%, and non-neck type 9.0%. In case of the neck type calices only, there found a correlation between numbers of calices and thickness of the kidneys.
3) The surface area of one minor calices, the total surface area of minor calices, and the mean surface area of them in each kidney were calculated. Both averages of total surface areas in 100 kidneys and of the surface area of one minor calyx in 858 calices were 356.71mm² and 41.55mm² respectively. In addition, the mean surface area of minor calices in each kidney was negatively correlated with the number of minor calices (r=-0.467, p<0.05).

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We performed histological and histochemical investigations on the so-called cardiac glands and esophageal cardiac glands in man.
1. The upper and lower esophageal cardiac glands are compound tubular glands.
2. The so-called cardiac glands are composed of the compound tubular glands and simple or simple branched tubular glands.
3. A few parietal cells are found in the cardiac, upper and lower esophageal cardiac glands.
4. Pepsinogen granules can be found in the basal, body and neck portions of the simple or simple branched tubular glands in the cardiac region, in the terminal portions and ducts of the compound tubular glands in the same region and in the same portions of the upper and lower esophageal cardiac glands.
5. The cardiac glands and esophageal cardiac glands contain neutral, weak and strong acid mucopolysaccharides, sialomucin and neutral mucous of types II and III.
6. The fundic glands also possess the above-mentioned items 3-5. The authors believe that the fundic, cardiac and esophageal cardiac glands are the same kind of gland.
7. The authors presume that the esophageal cardiac glands and the compound tubular type of the so-called cardiac glands are an aggregate of the fundic glands. Namely, the terminal portions and ducts of the same glands correspond to the fundic glands.
8. The authors consider the compound tubular structure of the esophageal cardiac glands to be more advantageous than the scattering simple tubular glands to the mechanical injury which is produced by the passing of food.
9. The epithelium in the excretory ducts of the esophageal cardiac glands and compound tubular type of the so-called cardiac glands reacted strongly to PAS. This characteristic is common to that of the gastric pits. The epithelium in the same ducts of the esophageal glands was PAS negative.
10. Some scholars presume that the upper and lower esophageal cardiac glands are the partially transported cardiac glands in the esophagus and another scholar considers that the lower esophageal cardiac glands are the ectopic gastric mucous membrane in the esophagus. However, the authors deny these opinions and maintain that the cardiac glands of the compound tubular type are the extended portions of the lower esophageal cardiac glands. The authors presume that the esophageal cardiac glands are normal structure in the esophagus and embryologically develop from the cranial side to the caudal side. Incidentally, several esophageal glands occasionally enter into the cardiac region.

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The effect of a single subcutaneous injection of monocrotaline on the right atrial muscle cells of rats was examined by electron microscopy. Particular attention was paid to changes in the number of specific atrial granules containing atrial natriuretic polypeptide, and to the degree of development of the Golgi apparatus in the cells induced by the drug.
The effect of the drug was maximum at 5 weeks after injection of 60 mg/kg monocrotaline. The Golgi apparatuses were markedly developed, and an increase in the number of specific atrial granules was observed in the central sarcoplasmic core, in the sarcoplasmic layer and under the plasma membrane of the atrial muscle cells. Swelling and increased numbers of mitochondria and swelling of the sarcoplasmic reticulum were also noted. The number of granules and development of the Golgi apparatuses were decreased at 7 weeks after the injection when cell degeneration became apparent.
These findings support the idea that the synthesis of atrial natriuretic polypeptide is accelerated by an increase in the atrial pressure.

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Three-dimensional observations of the vascular system of molar pulps in adult crab-eating monkeys were examined by light, transmission and scanning electron microscopy. The pulp tissue was reduced in size by secondary dentin formation which caused bifurcated roots on the mesial side of the radicular chamber in the mandibular first molar. As a result, the arrangement of blood vessels could be divided into two parts. Capillary networks were relatively rich in the pulp horn and peripheral side of the coronal chamber, while in the radicular pulp the capillary network was relatively sparse. Transmission electron microscopy revealed that small nerve fibers were closely associated with the arterioles of various sizes. Nerve fibers containing small clear vesicles and a few large and small dense-cored vesicles were observed near the arterioles, and the nerve terminals were considered to be adrenergic. These complex features observed in this study are thought to be related to the regulation of the local blood flow in the monkey molar pulp.

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In three individuals (#1, #2, and #3) among 906 adult rabbits, in which vascular casts and dissection specimens of the whole vascular system prepared by acryl plastic injection were examined, the left common carotid artery was found to be defective.
The aortic arch in each of these three cases was located at a normal height. The branches of the arch in usual cases in the rabbit were the brachiocephalic trunk and the left subclavian artery. This trunk trifurcated into the left and right common carotid arteries and the right subclavian artery, as seen in Type B of man (Adachi 1928). However, the left common carotid was not observed in each of the examples reported here. In the third example (#3), which was a dissection specimen, a remnant consisting of a connective tissue cord, instead of the left common carotid, was found. The right common carotid and right external carotid arteries were thicker than those observed in usual cases without any variations in their course and ramifications. The lingual artery in each of the three examples was rather thick and anastomosed strongly via a thick, hyoid branch with its opposite fellow. The left common carotid appeared as a fine vessel passing caudally from the bifurcation of the common carotid artery and became a fine cord of connective tissue which joined the brachiocephalic trunk. The bilateral lingual arteries were thick and anastomosed with each other. The hyoid branch of the lingual artery of the rabbit was always thick Through this anastomosis, the blood supply to the left half of the head was performed by ramifications of the right external carotid. It can thus be said that, prior to closure of the left common carotid, the above-mentioned anastomosis would have become much stronger.

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Synaptogenesis of the corticospinal axons was studied to examine the formation of neuronal connections of the corticospinal tract in the rat spinal cord of the postnatal period.
Most of the right cerebral hemispheres of the rats at 1,7 and 14 days after birth were destroyed with the electrical generator. At 1,2,3,4,5,6 days after the operation animals were fixed, and the cervical cord was observed using the electron microscope to identify the synaptic connections of the corticospinal axons occurred their degenerated changes.
At 1 day after birth, the corticospinal axons made synaptic connections with small dendrites, somata and axons of neurons in the intermediate zone and posterior horn contralaterally. A few synaptic connections of these axons were found in the same areas ipsilaterally. At 7 days, synaptic connections of the corticospinal axons were mainly found in the contralateral intermediate zone and posterior horn. In these areas various synaptic connections appeared as follows: the corticospinal axon formed synaptic connections not only with a dendrite or a soma, but also with several dendrites or axons. At 14 days, most of corticospinal axons distributed mainly in the posterolateral region of the posterior horn contralaterally, and formed various types of synaptic connections. Some of them were identified as the central axons in the synaptic glomeruli of the substantia gelatinosa. These findings indicate that the corticospinal axon is involved in the sensory system of the rat spinal cord.

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Central localization of the cervical esophageal motoneurons was investigated in the rabbit, using the intramuscular injection of retrograde labeling tracers horseradish peroxidase or nuclear yellow. The nucleus ambiguus of the rabbit comprises four subnuclei, CoG, SGm, SGl, and DiG, according to our previous cytoarchitectual study, of which only the ipsilateral CoG was pertinent to the esophageal motoneurons. CoG is the abbreviation for a cell grouping formed by a compact arrangement of the smallest neurons of the nucleus ambiguus, and it is situated in the rostral half of the nucleus. Labeled neurons were found in the rostral two-thirds of the CoG at levels 1.2-2.9 mm rostral to the obex; at the most rostral level, they overlapped the facial motor nucleus for about 100μm rostrocaudally. Their mean total number was 172, and they were more numerous in the rostral one-third of CoG than in its middle one-third. In a transverse section of the brain stem, labeled neurons at the most caudal level, although a few in number, were found in the lateral portion of CoG. More rostrally, at the mid-levels of CoG, in which the CoG was divided into two subgroups, ventrolateral and dorsomedial, labeled neurons increased in number and were distributed in the entire portion of the former subgroup. Furthermore rostrally, at the rostral levels of CoG in which no further division was found, they further increased in number and were distributed caudally in the dorsal half of CoG and rostrally in its entire portion.

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Nonciliated bronchiolar epithelial (Clara) cells of the rat, mouse, guinea pig and hamster were examined by transmission electron microscopy. The luminal surface of the cell was dome-shaped and its central protruding cytoplasm, an apical cap, was covered with microvillilike projections. The cell cortex just beneath the cell membrane of the apical cap consisted of homogeneous matrix. The center of the apical cap was filled with granules, mitochondria and smooth-surfaced endoplasmic reticulum. By perfusing lungs of the four different species with a medium containing detergent, the cytoplasmic matrix of the apical cap was extracted and filaments were found in all the animals examined. The region associated with the plasma membrane was electron-dense and often had a filament network. The presence of filaments and its close relationship with the cell membrane suggest that these filaments play an important role in the discharge of granules and/or in the maintenance of organelles, especially the abundant smoothsurfaced endoplasmic reticulum, in the apical cap.

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