A basic study on intracutaneous reaction to canine filariasis was performed with 67 spontaneously and 31 experimentally infected and 24 uninfected dogs. The antigen used had been prepared from the body of adult canine filariae. The worm body was dried to powder, which was suspended in phosphate buffer solution, treated with sonic waves of 10 kc, fractionated with acetone, and then freeze-dried. The antigen for intracutaneous injection was 0.01 per cent solution of freeze-dried powder in physiologic salt solution.
Intracutaneous reaction was observed after a dog had been injected intracutaneously at the hypogastric region with 0.1cc of antigen solution (containing 10 mcg of antigen). The positive reaction was identified with a distinct swelling more than 10mm in diameter appearing 15 minutes after injection and accompanied mostly by redness. According to this criterion, positive reaction was shown by 92.5 per cent of the spontaneously infected dogs, regardless of the presence or absence of young worms in the blood. Negative reaction was manifested by all the uninfected dogs, even those harboring canine ascarids, hookworms, whipworms, and tapeworms. No group reaction was recognized with any of these intestinal parasites.
The interval between experimental infection and the first appearance of positive reaction was 2 days at the shortest, within 30 and 121 days in 97 and 100 per cent, respectively, of the experimentally infected dogs. In short, it was made clear that intracutaneous reaction became positive in the very early period of infection.

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Precipitation reaction was performed with extract of horse meat as antigen. The antibody used was serum immunized by horse hemoglobin and possessed of a precipitin titer of 1: 12, 800. As a result, precipitin titers of 1: 800 to 1: 1, 600 were obtained, although there were differences between individual animals and between locations of muscles in the body. There is nearly a coincidence in results between the precipitin titers obtained and the amount which was presumed to be due to the hemoglobin contained in the muscle.
A precipitin titer of 1: 6, 400 was obtained when precipitation reaction was carried out with serum immunized with heated hemoglobin as antibody and with untreated hemoglobin as antigen. It is indicated from this reaction that precipitation test may be applicable to the differentiation of heated meat.
In precipitation reaction conducted for the differentiation of meat derived from different animal species, it was observed that the strongest reaction was obtained when immune serum had been diluted 2 to 4 times with normal rabbit serum and heated at 37°C for 15 to 3a minutes.
A mixture of meat derived from different animal species was tested by precipitation reac ion with serum possessed of a precipitin titer of 1: 12, 800 as antibody. The presence of horse meat was clearly demonstrated, since a precipitin titer of 1: 400 was obtained from a specimen containing 25 per cent horse meat.

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Studies on tuberculous pigs in Japan by some authors made it clear that the isolates from them, were usually human type tubercle bacilli (HTB). This finding is different from the high incidence of avian type tubercle bacilli (ATB) among tuberculous pigs in Europe and America.
The present studies consisted of intradermal tuberculin testing and pathological examination of young piglets experimentally infected with two strains of HTB, one strain of bovine type (BTB), and two strains of ATB. The two strains of ATB were proved to be virulent causing fatal tuberculous infection in chickens. Heat-concentrated synthetic-medium tuberculin was prepared from culture of HTB and BTB or of ATB. The potency of avian tuberculin was proved to be satisfactory when examined on chickens infected with ATB. Both types of tuberclin were used at twofold dilution in the tuberculin testing of piglets. The increase of thickness at the injected site was read at the 24th, 48th, and 72nd hour.
A reaction higher to mammalian tuberculin than to avian tuberculin was usually observed in tuberculin testing on piglets infected with HTB or BTB. Contrary to this finding, a reverse relationship in tuberculin testing was observed in piglets infected with ATB. From these results, the type of the causal agent in a tuberculous piglet could be identified from the results of a comparative method in accordance with many other authors findings.
In piglets infected with virulent BTB, generali zed tuberculosis was observed involving lung, liver, spleen, and their neighboring lymph nodes. Usually tuberculos lesions were limited to the inoculated site and its neighboring lymph nodes in piglets infected with ATB. The distribution of tuberculous lesions was observed to be more slight in piglets infected wih HTB than in those infected with BTB. The pathogenicity of the strains of HTB used in this experiment was rather attenuated.

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