We carried out dissections of about 40 or more kinds of wild animals in a zoological garden, and will report one after another the patho-anatomical findings of them. In this paper we reported about 2 cases of heavy malformatoin in sus scrofa leucomystax. The materials were embryos of twins, abortives from parents of same venter. The first case was almost mature female embryo. Patho-anatomical findings were, a) aplasia of facial portion, b) aplasia of os lacrimale, os nasale, c) hypoplasia of mandibular and maxilla, d) aplasia of meatns acusticus externus, e) aplasia of eyes, nose and mouth, f) trace of right auricula, g) splenomegalia, h) Adhesion of entrails, i) fibromatous nodules in pylorus. The second case was also female embryo, but far smaller than the first. Patho-anatomical findings were a) aplasia of facial part, b) aplasia of eyes, nose, maxillar and maudibular bones, c) aplasia of the other facial bones, d) aplasia of meatus acusticus externus, e) branchiogenic fistulas on both side, f) hypoplasia of heart, g) hypoplasia of pulmonal arteries and aorta, vena cava cranialis, h) hypoplasia of vena unbilicalis.

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A female kangaroo in zoo missed her embryo in her maruspium on 16/I, 1956, and then she became more and more inactive and unhealthy. She died suddenly on 21/IV, 1957. we dissected her 23 hours after death. Findings were as follows, 1) Acute Pneumonia. 2) Fatty Heart. 3) Marasmus. 4) Nephrosis. 5) Atrophy of the spleen.

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A male patient, 41 years of age, who was hospitalized by unidentified illness, later proved to have primary lesion in his mouth due to diphtheria which eventually caused his death. There was observed no pathologic change in his throat as it ought to be, and instead, patches of darkish, white pseudmembrane had covered those regions of the mouth facing the molar teeth of upper and lower jaws, and from thence an organism identified as the true Corynebacterium diphtheriae was isolated. Besides this, a variant organism of Corynebacterium with different characteristics was isolated by culture from the patient′s blood circulation. The latter organism showed its own cultural and sugar-fermenting characteristics distinct from the members of the same species as described in Bergey′s Manual of Determinative Bacteriology (1948). It was also confirmed that the organism was pathogenic to guinea pigs and rabbits. It must be added that the autopsy clearly decided the cause of the patient′s death as due to diphtheria.

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Biometric measurements have been conducted on the distances from every incisal edges and occlusal tips of upper and lower dentitions to the Camper′s plane. A total of 94 individuals consisting of 44 males and 50 females from 18 to 23 of age were selected as the subjects according to a criterion that their teeth were sound in every respects, free from marked attrition and erosion, and the occlusion was normal as strictly as possible. Plaster models were prepared from alginate impressions of upper and lower jaws, and these were mounted on the specially designed apparatus following the preparation tecnipue of gnathostatic model routinely used in the orthodontic practice. On this jaw model, the basal plane of upper jaw was placed so as to come parallel to the Camper′s plane. In Fig.1 and 2 the method and apparatus were illustrated. The conclusions were reached as follows. It was confirmed that the plane including the mesial incisal edges of both central incisors and the buccal distal cusps of both second molars in lower jaw was not parallel to the Camper′s plane as it has been supposed so, because the present study has revealed that the former point of jaw were closer than the latter points to the Camper′s plane by 1.5 millimeters. Hence, for the purpose of utilizing the occlusal plane in denture work which is nearest parallel to the Camper′s plane, one would have to select either the one which connects the buccal cusps of both first premolars and the buccal distal cusps of both second molars in lower jaw, or the one which connects the buccal distal cusps of first and second premolars and the buccal distal cusp of first molar in upper jaw. Also it must be noted that in upper jaw the buccal distal cusp of first molar is lower than its mesial cusp, and among all the cusps in buccal side those of the first and second premolars are the lowest, while among all the cusps in lingual side the mesial cusp of first molar is the lowest. In lower jaw, the distal cusp of first molar is lowest among the buccal cusps of all teeth, while among the lingual cusps that of first premolar is lowest. The author believes that these facts as revealed in the present study must be taken into account by the clinicians in the practice of arranging the artificial teeth on denture plate.

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Although many investigators have so far made contributions to the knowledges about the innervation of tooth tissues of higher animals, there remains as yet a vast amount of informations to be supplemented in more details. Continued to a series of study in this field, the present report has described particularly on the innervation patterns in the teeth of dogs and cats. 1) In the monoradicular teeth of both animals, a bundle of nerve fibers distributed to a tooth branches as soon as it comes into the tooth through the apical foramen and directly ascends upward along the wall of the root canal, while in the multiradicular teeth it straightly ascends the root canal along the long axis of the tooth without branching till it reaches the pulp cavity. 2) Having reached the pulp cavity, most of the nerve bundles turn to branch numerously, covering still the wall of dentin. 3) The running course of the nerve fibers in the pulp horn of molar teeth is radial in the dog, like thick tuft in the cat. 4) Blood vessels and nerves in the tooth generally run together in both animals. 5) The way in which the unmedullated nerve ends in the pulp cavity is classifiable into 3 types. 6) The nerve fibers in the tooth germ are extremely fine in structure as compared to those in the completed tooth. 7) All the endings of nerve fibers in the pulp cavity terminte in contact with the odontoblasts, and nothing of the nerve fibers is seen in the dentin tissue.

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Since Katayama (1887) first made investigation on the splitting-lines occurring in the crania of newborn infants, study has been urged toward elucidation of archtectural basis of the compact substance of the bones, and along with it, biological significance of the splitting-lines has become an object of arguments. In our laboratory where main effort has been devoted to detailed studies on the nature of tissue splitting, deliberate reexamination of bone′s splitting-lines from every angles is now under way. Nakayama, director of the laboratory, in summing up the works done under his supervision, has made a comment on previous authors′views and has pointed out that many of the authors usually focussed their attention merely on the normal splitting-line systems without paying much regard to the irregular splitting-lines occurring rather not infrequently during observation, and probably they failed to grasp the full meaning of the splitting-lines due to negligence of the sequence of time of their occurrence. He has concluded that the splitting-lines were consisted of normal line system and irregular splitting-line, and these two collaterally provided the useful tool by which certain developmental phases of the bone could be well interpreted. He also laid emphasis to the fact that while the normal splitting-lines indicated the growth direction of the bones, the irregular splitting-lines, being produced by disturbance of the former, manifested direct functional response of the bones. In view of the recent trend of study which mainly concerned with mechanical and functional analysis of simple line systems rather than with careful follow-up of line systems as they change with age, the present author decided to make observation in the dog′s mandible on how the architecture of the compact substance was to experience changes with each stage of animal′s development and how they would appear. The conclusions reached of these observations were summarized as follows. 1) Male dogs of the red, short hair type, including embryos aged two months and those post-natal animals aged respectively one, three and six months, and one, three, five, seven and eight years, were used as materials, and the splitting-lines of these animals′mandibles were studied. 2) The varieties of these splitting-lines, when observed perspectively as they appear through all the stages of development, can be understood to constitute a series of changes corresponding to each age stage as well as to ever increasing functional activity of the animals. 3) The sequence of these events is outlined as follows. The first stage (two month embryo) : This is incipient stadium of growth where two independent line systems forming bases of the future developmnt are noticed in the mandible, and here the irregular splitting-lines are lacking. The second stage (one to six months after birth) : This is the period when marked growth takes place in the mandible. At three months after birth, growth in the alveolar part of the mandible toward vertical direction gives rise to a well-developed line system, and at six months after birth, growth toward antero-posterior direction gives rise to another distinct line system. These normal line systems are accompanied by two kinds of irregular splitting-line mass, the one occurring at three months after birth which suggests development of the masticatory function, the other occurring at six months after birth which is supposed to point at change of growth direction. The third stage (one to five years after birth) : This is the period of growth completion when the vital functions of animals are most vigorous. Here occur distinct masses of the irregular splitting-lines at the muscle insertions, especially at one to three years of age. The forth stage (seven to eight years after birth) : This is the period when atrophy of tissues begins. The line systems in the mandible are changed here into masses of the irregular splitting lines.

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[in Japanese]

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