The enamel tubes of the jaw teeth of Pagrosomus major and Taius tumifrons, and the jaw and pharyngeal teeth of Semicossyphus retieulatus were observed usingground sections. The ground sections were examined with the telemicroscope using transmitted light and as microradiagraphs. The enamel tubes penetrated into the enamel perpendicular to its surface, and their diameters were widest at the outer surface, diminishing through the deeper layer. Each enamel tube ramified with two or more, branches which bend in various directions. The tubes terminated by bending and tapering long before they reached the dentino-enamel junction. The historadiographs show that the enamel tubes of these fish are true tubes. Correct focusing of the ground. sections seen with the high magnification possible with the television microscope shows. that the enamel tubules are real, and that the dark granules are due to an optical effect.or Becke line.
The dentin of porgies and Semicossyphus were also examined, using ground sections with transmitted light and historadiographic methods. No peritubular hypercalci fied zone appeared in the dentin of these fish. Correct interpretation of photomicrographs, that is, by recognizing the Becke line, the ground sections of fish dentin show just as it does in human dentin, that there are no Neumann's sheaths or Tomes' fibers in this processed tissue

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With a view to investigating into the pathogenicity of oral Staphylococci carefully collected from the pus of the infectious diseases in the oral cavity, the authors compared the strains derived from the infectious, oral flora and Acne vulgaris strains and looked into their properties in terms of α-toxin, coagulase production, mannitol dissolution and acid resistancy which are closely related to the pathogenicity. The following are the salient findings of our study on the subject.
1. As regards 19 infectious strains, 17 cultures gave pathogenic Staphylococcus aureus and 2 cultures non-pathogenic Staphylococcus epidermidis. 11 strains out of 17 identified as Staphylococcus aureus produced a potent α-toxin.
2. As regards the normal flora strains, 49 out of 58 saliva cultures were determined to be Staphylococcal. Of these cases, 39 strains were Staphylococcus epidermidis and 11 strains Staphylococcus aureus, 9 strains of the latter attesting to the production. of α-toxin.
3. All of 14 strains derived from Acne vulgaris were Staphylococcus epidermidis. and the production of a-toxin was not detected at all.
4. The sensitivity test on 6 antibiotic drugs revealed that 10 out of 19 infectious strains, 3 out of 14 normal oral flora strains and 10 out of 14 Acne vulgaris strains. possessed resistant property against penicillin. High sensitivity was observed on the part of other 5 antibiotics.

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More recognition has come to be given to fungi as a pathogen, following those of bacteria, Rickettsiae and viruses, in connection with the increasing application of various antibiotic drugs, impetus being due to the so-called 'microbisme sélectionné et substitué'
Cases of mycosis which have been so far most common in Japan are candidasis and actinomycosis but, in recent years, it was brought to the attention of scientists that mycosis of aspergillus has a trend to increase. According to MIYAKE et al.[1], it was found thet cases of actinomycosis decreased while those of aspergillus increased with those of candidasis surprisingly small. At any rate, it is within the past decade that medcal mycology has come to clai a wider attention.
Although there are available many research findings as regards candidae and actinomycec as coming under the oral flora eumycetes, published literature is yet scanty concerning aspergillus[2].
The present paper relates to the detection of aspergillus in connection with the periodontal infection undertaken by the authors.

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The author has investigated the vital response of the juvenile patients to various noises and music both experimentally and clinically. As a consequence of study described above, he obtained the following conclusions.
1. Experimental Study.
(1) When living bodies were exposed to the defnite sound stimuli, responses to be observed varied from person to person.
(2) When other external stimuli were introduced not pertinent to sounds for study, G. S. R. reflexes were influenced largely as a result. When a person moved his body, there took place a large G. S. R. reflexes near the fixed electrode.
(3) There were observed no G. S. R. reflexes prior to and subsequent to an operation, when the patients were relaxed.
(4) When various noises were received by the patients concurrently with music, as a whole large reflexes took place around 500 c.p.s., 700 c.p.s. and 1000 c.p.s. This is explained by the fact that the human sensitivity to hearing is most keen around the frequency of 700 c.p.s.
(5) Magnitude of G.S.R. reflexes was greater when the patients were exposed simple to noises than when music was conjointly used with these noises.
2. Clinical Study.
(1) G.S.R. reflexes were much smaller when the patients were treated while music was being broadcast than when they were treated conventionally.
(2) Magnitude of reflexes at each stage of the treatment was much less when music was concurrently employed with the treatment.
(3) When the patients showed large G. S. R. reflexes while under the treatment listening to music, the reactions should be rather ascribed to an operator's behavior toward the patients.
(4) When a patient moved his body, the same sort of G. S. R. reflex took place as in the basic test.
(5) The type of music which was used in the present study was low-toned one with fairly monotonous beat but its effects in masking noises to the benefit of juvenile patients were well attested.
As general conclusion of both the experimental and clinical studies, the use of background music used in a special manner above described will definitely enhance the treatment efficiency by removing the emotional tension and, at the same time, stabilizing the mind of juvenile orthodontic patients.

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It is a matter of common acceptance that the form of dental arch is influenced more or less by the positions of teeth and, at the same time, the positions of teeth vary not only in terms of individual differences in the positions themselves but also in terms of individual differences in the size of dental arch and differences in the size between upper and lower jaws.
In the present paper, the authors are concerned with the measurement on the relative positions of teeth, properly eliminating these differences based on definite standards, so that we might determine differences of the relative positions of teeth owing to age, sex and jaw in the measured data. An effort was further made to look into a relation between the relative positions of teeth and the average form of dental arch concerned.

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4 successive zones are distinguished in the enamel caries cone through the electron microscopic observation from the outermost zone to the deep zone : 1) a zone of remarkable destruction, containing abundant bacteria and debris, 2) a zone of partial destruction which is poor of bacteria, 3) a zone of incomplete demineralization and finally, 4) a zone of apparently normal enamel.
Carious defects of apatite crystals are the first manifestation of carious destruction detected by electron microscopy. The zone of incomplete demineralization is thus formed. Even at this earliest stage of carious destruction, the dissolution of organic components seems to break out more or less with the subsequent appearance of crystal defects. At the more advanced stage, the appearance of bacterial invasion is brought about and the zone of incomplete demineralization changes into the zone of partial destruction poor of bacteria that is situated directly above the former. Bacterial invasion is not found in any special structures of the enamel but appears in the rod, rod sheath and interrod substance contemporaneously. Bacteria seem to destroy the enamel to a limited degree that they can invade there. Following this stage, bacteria remarkably increase altogether with the heavier progress of carious alterations, and frequent portions of the carious enamel are mostly filled with a large number of microorganisms. The enamel is most heavily destroyed and, at a glance, represents itself in the homogeneous state, in which enamel ruins are barely detected. At this stage, the zone of partial destruction which is poor of becteria turns into the zone of remarkable destruction containing rich bacteria and debris, located immediately above the former as the outermost zone of caries cone.

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