Relacement of temporary with permanent teeth was studied on 1400 male and female subjects, aged 6 to 15 years old and living in Yunoura-machi, Kumamoto Prefecture and 1098 male and female sudjects, aged 6 to 15 years old and living in island Amakusa, Kumamoto Prefecture. Comparison was made with the data obtained respectively from groups of 1124 male and female subjects, 6 to 15 years old and living in Kitsuki city as examined in 1958 by Anan, and also from groups of 1746 male and female subjects, 6 to 15 years old and living in Kumamoto city as examind in 1950 by Ninomiya. The total numbers of being 5368 of male and female sex. The results were summarized as follows. 1. The average numbers of existing deciduous teeth Yunoura-machi Amakusa district} : Male>Female Male : Kitsuki city>Yunoura-machi<Amakusa district Female : Kitsuki city≒Yunonra-machi≒Amakusa district Male and Female : Yunoura-machi<Kumamoto city (1950, Ninomiya) 2. The average numbers of erupted permanent teeth Yunoura-machi Amakusa district} : Male>Female Male : Kitsuki city>Yunoura-machi<Amakusa district Female : Kitsuki city≒Yunoura-machi≒Amakusa district Male and Female : Yunoura-machi<Kumamoto city (1950, Ninomiya) 3. The average ages for permanent teeth eruption were expressed as follows Yunoura-machi Amakusa district} : Male>Female Male : Kitsuki city>Yunoura-machi<Amakusa district Female : Kitsuki city≒Yunoura-machi≒Amakusa district Male and Female : Yunoura-machi<Kumamoto city (1950, Ninomiya)

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It is a well known fact that thorough chewing of food is favorable for the health. This favorable effect of chewing seems to be due, not only to mastication of food, but to some action of saliva secreted during the chewing. With the object of confirming this supposition, young rats were fed with food mixed with saliva and the growth of them was compared with that of control animals. Young albino rats of the same litters were divided into three groups after breast feeding for ten days after the birth : The first group was fed with rat milk only, the second group with rat milk and powdered cow milk, and the third group with powdered cow milk mixed with human saliva, each for 14 days. On the 25th day the first and the second group were fed with corn mixed with fish meal. But the third group was fed with corn and fish meal mixed with human saliva. After 39th day all three groups were fed with the same food. The saliva used in the experiment was collected from healthy human beings with small tubes devised for the purpose. Three kinds of the saliva were used, (i) the parotid, (ii) the submaxillary and sublingual, (iii) the mixture of the three. The body weight of animals was measured day after day. Taking the body weight on the first experiment day as 100, the subsequent weights were expressed as indexes and compared one another. Graphs depicting these indices show evidently that the growth of the third group fed with the food mixed with the saliva surpassed those of the other two groups. But the effect of the three kinds of saliva was not the same ; the submaxillary and sublingual saliva, and the mixture of the three were effective, but the parotid saliva showed no effcct. Besides, the saliva collected during and after meals proved to be more effective than that obtained before meals. As the submaxillary and sublingual saliva contains more mucin and protease, to these components the favorable effect of the saliva observed on the body growth of rats seems mainly to be attributed.

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Age changes of the splitting lines occurring in the visceral wall of the tunica vaginalis propria testis have been observed in dogs, and the following four stages of developmental phases were noticed. The first stage : This corresponds to the period from the first month of birth to the third month where the splitting lines occurring in the ventral surface run generally longitudinally and those occurring in the medial and lateral surfaces tend to converge toward the caudal end, and these constitute arched line systems dispersing antero-interior and antero-exterior side respectively. There were noticed several masses of irregular splitting lines at the posterior half of each line system. The second stage : This comprises the period from the third month to the eleventh month of the animal where the arched line system hitherto shown assume more increased curvature and sometimes take even S-form. In the general view, however, there is the impression that the arched line systems have turned into irregular ones, and in fact there also appear marked masses of the irregular splitting lines. The third stage : This corresponds to the period from one year to four years of age of the animal where the splitting lines assume most complicated picture along with full development of the testis. There is seen strong winding of the splitting lines in S-form and increased number of the arched line systems together with the increase of the sites in which the irregular spritting lines are seen. The fourth stage : This includes the poriod from six to eight years of age in which the testis has undergone considerable diminution in size. The curvature of the splitting lines tends to be more flat and gives more simplified appearance. However, there in the posterior half of the ventral surface one notices a region showing marked masses of irregular splitting lines. These finding seem to indicate that fhe period from five months to four years of age of the animal represents the time in which the testis displays most vital function of its own as evidenced by the occurrence of the masses of irregular splitting lines. However, by six, seven and eight years of age of the animal, all the arched line systems become simplified and flat in their curvature, and the mass of the irregular splitting lines becomes to be restricted to a single region of the wall to show atrophic condition of the organ. These changes in the splitting lines shown in the visceral wall of the tunica vag. propria testis in dogs should be interpreted as representing the structural development of the tunica of the testis. To put it more particularly, the splitting lines occurring in the serous membrane of the tunica not only undergo influence of the development of its substantia exerted from within, but also are influenced by various mechanical and dynamic factors from outside, and these are left imprinted on the splitting lines as they themselves go developing through each stage of animal′ life

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The percent emulsion in saline of rat's gingival tissiue slice was injected into rabbit's ear vein in amount of one to two ml twice to 18 times, and high production of the antibody against the tissue was confirmed in the latter animal by means of precipitation and complement-fixation reactions. It was confirmed that by injecting the rabbit's antiserum into the caudal vein of healthy rats, a gingival lesion to be observed even by the naked eye could be produced. It was decided, therefore, that this substance be named "Gingivotoxin" to be ranked in a member of the cytotoxins affecting specifically gingiva. The results of the study are summarized as follows. 1) When the animals were subjected to immunization with the saline emulsions of gingiva (G group), of parotid (P group) and of tongue (Z group), the rates at which they died of shock were respectively 63.5 percent in G group, 50 percent in P group, and 40 percent in Z group. 2) The pathological processes occurring in G group of animals were primarily different from those observed in the other groups in that there appeared in the basement membrane at the interdental papillae severe anemia and epithelial cysts accompanied by cellular infiltration of the epithelia. The cysts enlarge, and with that enlargement comes liquefaction of the tissue involved which finally leads to necrosis of Sharpey's fibers. 3) In parallel with these macroscopic lesions seen in the gingival tissue, there were observed microscopically relatively weak changes taking place in such organs as spleen, kidney and lung whereas no change was detected occurring in the hard tissue and the pulp of teeth even by microscopic examination. The results of the experiment suggested a possibility that such a necrotic lesion of gingiva and periodontal membrane might be somehow induced also by the action of autotoxin of gingiva according to the theory of inverse allergy or metallergy, and if this happens, the present study may serve to lend a support to the allergic theory for the ethiology of one type of socalled pyorrhea alveolaris.

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Splitting lines of the bone have been so far studied systematically in our Laboratory using various vertebrae animals from the view point of comparative anatomy. It has been revealed from these studies that the splitting lines of the bone represented the developmental phases of the bone through whole stages of animal's life of which the line system indicated the direction of growth and the irregular line mass was the direct sign of bone's functions. Assuming that the same situation with the compacta of the bone would hold true to the cartilage with respect to the role of splitting lines, the author undertook to make observation on the developmental changes of splitting lines as examined in the cartilage of articularis temporomandibularis and the discus articularis in dogs as a part of the studies on this line. The results were summarized as follows. 1) In this study various phases of the splitting lines as manifested in the cartilages of dogs with their growth through every stages of life were described. 2) The phases of the splitting lines as observed throughout the life cycle of animals can be summarized in two different categories, of which the one representing age changes of their morphological patterns, the other the same morphological changes but corresponding to ever increasing complexity of vital functions imposed on the bone. 3) The first stage (the embryo 60 days old) : This represents the primary stadium of development where only the irregular splitting lines are to be observed in these cartilages. The second stage (One to five months after birth) : This is period of vigorous growth of the animal where two basic line systems for future development are observed in these cartilages. One of the line systems runs vertically and the other runs from the middle of the inner side toward the antero-posterior margins, both being well developed. There are also observed two masses of irregular splitting lines, one representing the disturbance of growth direction, the other suggesting initiation of the masticatory function in the animal. The third stage (7 to 12 months after birth) : This is the time of growth completion where the line systems assume growth direction similar to those observed in the second stage and there appears irregular mass of splitting lines suggesting vigorous strain of masticatory function of the animal. The fourth stage (2 to 5 years old) : Here the animal completes its growth and its masticatory function represents one of the most vigorous functions of the body. This is reflected in these cartilages by alternating arrangement of the disturbed pattern of line system and the normal line system as result of its repair. 4) The line systems occurring in the fossa mandibularis and capitulum mandibulae run toward the same direction, indicating that the site receiving the most severe stress of mastication is the inner part of these cartillages.

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A lama glama died from sun-and heat-stroke after very hot and humid days in summer of 1956. Causes of death were not, otherwise, recognized. We dissected the animal and obtained following findings ; 1) High degree of stagnation in the region of N. splanicus. 2) Stagnation and edema of both lungs. 3) Edema of epiglottis. 4) Subendocardial hemorrhage (right ventricle and atrium). 5) Slight degree of cloudy swelling of liver and kidneys. 6) Fluidity of the blood.

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Similarities in the tooth curve of the dental arch, in the morphological patterns of the dental arch and the palate existing among twins, brother and sister, and parent and children were studied. The regulative curve of the dental arch was measured in the following manner : A Plane was established on upper jaw which included four points in it consisting of mesio-palatal and disto-palatal cusps of the right and left molars, and this plane was conveniently called "The first molar plane" by the author. The heights from this plane to individual teeth of the dental arch were measured in this study, taking the middle points of incisal margins, tips of the cuspids and the cusps of every posterior teeth as measuring bases. The results were summarized as follows. 1) The heights of teeth : The height of the first molar was the lowest, and it became higher successively in the order of the teeth locating frontally. 2) The heights of every teeth were lowest at the age of 15 which increased slightly thereafter. 3) There was hardly any noticeable difference with sexes in the heights of teeth of both sexes. 4) In the similarity study of the tooth height among children of the same parent, it was revealed that there was hardly noticed any difference between brothers and between sisters, and the similarity was the least between elder sister and younger brother, and between elder brother and younger sister. In the similarity study of the regulative curve, it was observed that there was hardly any difference in similarity to be found between brothers and between sisters, and that there was least silmiarity between the male and the female members. 5) The similarity in the tooth height among parentand children was expressed conveniently in the following simplified formulae. father : sons&le;farher : daughters mother : sons≦mother : daughters father : sons≒mother : sons father : daughters&ge;mother : daughters 6) The correlation coefficients of the tooth heights among consanguinous children were as follows. Correlation Coefficients male : male……0.051-0.508 female : female……0.002-0.434 male : female……-0.006-0.302 7) The correlation coefficients between the tooth height and the dental arch breadth, dental arch length and between the palate height were as follows. male……-0.049-0.511 female……-0.039-0.520 The correlation coefficient between the height of first molar and the posterior palatal height proved to be greatest. 8) The correlation coefficientsof the incisal overbite among consanguinous peoples were as follows. Identical twins……0.68-0.86 Fraternal twins males : males females : females}……0.47-0.81 males : females……-0.06-0.14 Siblings……0.03-0.34 parents : children……0.04-0.33 9) The correlation coefficients among consanguinous peoples between the dental arch length and the dental arch breadth were as follows. Identical twins……0.44-0.88 Fraternal twins males : males females : females}……0.56-0.77 males : females……0.32-0.61 Siblings……0.03-0.57 Parents : children……-0.03-0.54 10) The correlation coefficients among consanguinous peoples in the dental arch index were as follows. Identical twins……0.25-0.77 Fraternal twins males : males fewales : fewales}……-0.23-0.76 maless : females……0.20-0.56 Siblings……-0.18-0.09 Parents : children……-0.07-0.35

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Lingual papillae were studied on a female kangaroo (Macropus giganteus) aged ten. 1) Papillae vallatae ; these were depressed from the surface of tongue, and the groove circumscribing each papilla assumed characteristic form in that it turned into a fine aperture about 0.3mm in diameter at the dorsal center of the papilia as if pouring out on the dorsum of tongue. They were relatively rich in taste buds. (Fig. 4) On this point they resembled in shape to those occurring in Schnabeltiere (Ornithorhynchus anatinus) as described in one of the Oppel's textbooks. 2) Papillae folliatae ; long oval in shape, they occur 7 to 8 each on one side of the tongue. They were very poorly furnished with taste buds as contrasted to the vallate papillae. 3) Papillae collicularis ; these occur on the tongue elevated like knolls having slight depression at each top. They are localized scatteringly on both lateral marsins of posterior half of the tongue. They lack taste bud, and instead, are provided with ducts of mucous glands. 4) Papillae fungiformes ; these occur at the frontal part of the tongue approximately ten in number on each side. 5) Papillae filliformes ; fine and slender in shape, they cover densely all over the dorsum of the tongue, and each papilla shows bifurcation at its free end.

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