Twelve pigs were divided into 2 groups: the 1st group of seven and the 2nd group of five. Each of them was given orally with 1.7×10⁶ sporulated Toxoplasma oocysts, which had been isolated from the feces of an unwanted cat and identified as those of Iosopora bigemina. All the pigs were examined for body temperature and symptoms every day. The 2nd group was fed a ration containing 500 ppm sulfamonomethoxine (6-methoxy-4-pyrimidinyl sulfanilamide monohydrate) and 25 ppm pyrimethamine (2, 4-diamino-5-(p-chlorophenyl)-6-ethylpyrimidine) for 7 consecutive days before the inoculation of oocysts and the following 58 days. All the pigs of the untreated 1st group showed an increase in body temperature, loss of vigor, anorexia, ocular discharge, coughing, tachypnea, diarrhea and cyanosis. All of them except one which was killed for pathological examination on the 7th day after inoculation died some time between the 9th and 15th day after inoculation. Histological examination of the 1st group revealed necrotic foci in some visceral organs, including lymph nodes and intestine, and encephalitis and inflammatory edema in both lungs. Suoh lesions as these were seen in no pigs of the 2nd group. Toxoplasma was detected from the pigs of the 1st group, but not from these of the 2nd group, and identified by Giemsa's staining and the mouse inoculation test.

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Eimeria tenella, E. brunetti and E. acervulina were cultivated in cell cultures, and their growth forms and cultivation conditions were investigated. The results obtained are summarized as follows. 1. E. tenella oocysts developed in cell cultures inoculated with sporozoites. E. brunetti grew to mature second-generation schizonts. No developing stage was found in E. acervulina. 2. In the cultivation of second-generation E. tenella merozoites, a few merozoites invaded cultured cells, but no further development was observed. 3. Schizonts were classified into three morphological types. Type I schizonts were identical with forms found in vivo. In type II, the cytoplasm of the schizont was divided into masses of various size. Each mass contained one or more nuclei. Type III schizonts resembled intracellular sporozoites, although they were clearly larger in size than the latter. They had a refractile body, a large nucleus, and abundant cytoplasm. 4. Three different ways were seen in the merozoite formation. Merozoites were formed from the segment of the type I schizont, spherical bodies of the type II schizont, and the periphery of the type III schizont. 5. The optimal conditions for the cultivation of E. tenella in vitro consisted in the use of chick kidney cells and medium No. 199 containing 0.2% yeast extract and incubation at 40°C. Satisfactory results were obtained from E. brunetti when chick embryonic fibroblasts were employed and when the culture was maintained in Eagle's minimum essential medium and incubated at 40°C.

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Seventeen cases of feline mast cell tumor, being 22% of a total feline tumor cases examined during 10 years, were studied pathologically. Mast cell leukemia was detected in only one out of 5 autopsy cases examined. In 3 cases, multiple skin lesions reported rarely in feline cases, were present involving the epidermis as well as the dermis with infiltration of a large number of neoplastic cells. In all cases the most prominent gross lesion at autopsy was marked swelling of the spleen and lymph nodes. Microscopically the spleen in most cases was occupied almost completely by proliferated tumor cells. The liver was infiltrated to varied degree with tumor cells, some of which were seen to be liberated into the sinusoid from subendothelial lesions. Many foci of tumor cells were formed in the lymph nodes and bone marrows, and the dissemination was seen in interstitial tissues of the lung as well as the glomerular capillaries without forming distinct masses. In each case tumor cells were of an almost similar morphology, and most cells were of immature type in 7 out of 17 cases, while of mature type in the remainings.

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Specific pathogen-free (SPF) ICR mice were inoculated intranasally with Mycoplasma pulmonis strain m53 and were observed during one-year period for the formation of pulmonary lesions, persistence of mycoplasmas and production of antibodies. Of the nasal cavity, the isolation rate was 100% during 3 months following inoculation, decreasing thereafter. While the organisms persisted for a longer period in the trachea than in any other sites of the respiratory tract, they were isolated only at a lower rate from the lung. Gross pulmonary lesions were first observed on the 2nd day after inoculation and, in earlier stage of infection, the incidence of pneumonic lesions correlated with mycoplasmal isolation rate, becoming a maximum 90% on the 20th day. Later, however, such correlation was not observed, although the incidence of lung lesions remained at 50% for 10 months. While the CF antibody was detected already 5 to 10 days after inoculation turning to negative in 90% of inoculated animals one year later, the IHA antibody was detected 20 or more days after inoculation persisting at high titers for one year or over. The MI antibody was first detectcd 2 months after inoculation at titers much lower than those in CF and IHA. In non-inoculated mice having been kept for 10 weeks as cage mates with inoculated ones, were found to have mycoplasmas and antibodies without no gross lesions in the lung.

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Mineralization of soft tissues was investigated in 7 young calves histologically and electron microscopically. It occurred to collagen and elastic fibers of cardiovascular organs. Circumscribed mineral deposition was present in the subendocardial. and myocardial stroma and the aortic media. Foreign body reaction was noted around the mineral deposit in the heart. Mineral deposition was also seen in blood capillaries of renal interstice, splenic trabeculae, thymic medulla, and germinal centers of mesenteric lymph nodes. Calcium and ferric phosphates were detected from mineralized lesions by histochemical analysis and x-ray microanalysis. Acid mucopolysaccharide was also demonstrated histochemically. Electron microscopy revealed mineral deposit in collagen fibers and crystals aggregated dispersedly or massively in fibrillar extracellular spaces in the heart. Collagen and fibroblasts were present around the aggregated crystals. Mineralization in elastic fibers was recognized in the aortic wall.

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In their previous report, the authors suggested that some part of the contents of the duodenum and ileum might be transferred conversely into the gizzard in chickens. It has been presumed that the antiperistalsis of the duodenum may probably be one of the factors of this phenomenon. Therefore, the present experiments were carried out to observe the relationship between the movements of the gizzard and duodenum and the transit of the contents of the duodenum. 1. By the abdominal-window method, it was witnessed that the movement of the gizzard was a strong and globular contractile one, that the peristalsis of the duodenum was an induced movement, and that immediately after the end of peristalsis occurred the antiperistalsis once or three times. 2. Relationship of the difference in the time of starting between the movement of the gizzard and that of the duodenum was observed simultaneously by the electromyographic, mechanographic, and abdominal-window methods. It was clear that the peristalsis of the duodenum occurred in the contractile period of the gizzard and that the antiperistalsis of the duodenum appeared in the relaxing period of the gizzard. The contractile pressure of the movement of the gizzard was 150-170 mm Hg. 3. Approximately 100 mg of bilirubin was measured in the gizzard. A volume of 0.2 ml of the marker (Na₂^&lt15&gtCrO₄) warmed at 38°C was injected selectively into the duodenum through a cannula which had been inserted chronically into the hepatic bile duct. In 1 hour, 18.9% of the dosed radioactivity was distributed in the gizzard. 4. In an in vivo experiment, atropine (0.2 mg/kg intramuscularly) suppressed markedly the contractile force and frequency of the movement of the gizzard and of the peristalsis of the duodenum. On the other hand, the contractile force of the antiperistalsis of the duodenum decreased slightly, but its frequency increased markedly. In these conditions, the same volume of the marker was injected into the duodenum, but no dosed radioactivity was distributed in the gizzard in 1 hour. The quantity of the marker distributed in the upper segment of the duodenum was larger in an atropinized chicken than in an intact chicken. It was approximately equal to that distributed in the gizzard in the intact chicken. There was no difference in the quantity of the marker in the lower segment of the duodenum or in the small intestine between the atropinized and the intact chickens. 5. From these experimental results, it was made clear that some part of the contents of the duodenum was regurgitated into the gizzard. Furthermore, it was assumed that some part of the intestinal contents around the opening of the bile duct into the duodenum might be transferred conversely into the gizzard by the interaction between the antiperistalsis of the duodenum and the change in pressure of the relaxing movement of the gizzard in the absence of the functional sphincter pylori.

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A chronic toxicity test was performed on rats with taselin by oral administration for 13 weeks. The tested doses were l00, 500 and 2500 mg per kg of body weight. 1. No abnormal clinical signs were manifested by any animal, except those given a dose of 2500 mg/kg which showed activity in behavior. Two of the female rats given 500 mg/kg died during the experimental period due to errors in the procedure of administration. 2. Hematological examination showed a significant decrease of leukocyte count in all the rats of both sexes given 2500 mg/kg. 3. When various organs weighed at autopsy, the spleen showed an increase in absolute weight and relative weight in the rats of both sexes given 250O mg/kg. 4. Hist-morphologically, a slight atrophy in the epithelial cells of renal glomeruli was found at the 2500 mg/kg does under optical microscopic examination as well as hemosiderine deposits in the spleen, but no particular finding was made under electron microscopic examination.

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