[in Japanese]

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As is known, various kinds of interesting tumours occur in the fowl. At autopsy of 3150 hens, 350 cases of leiomyoma, 1 case of rhabdomyoma, 3 cases of fibroma, 4 cases of lipoma, 7 cases of sarcoma, 8 cases of lymphoma, 1 case of malignant adenoma, 3 cases of cystoma and 37 cases of intra-abdominal carcinoma were found. In 270 cocks, however, only 1 case of sarcoma was found.
44 cases of carcinoma, including 7 cases which were collected from poulterers, have been studied histogenetically; it has been shown that 16 cases were resulted from the cells of oviduct gland, 1 case from the mucous membrane of oviduct, 9 cases from the paraovaries, 6 cases from the follicular cells of ovary, 1 case from the cells of the seminiferous tubule of the ovary, 1 case from the peritoneal ep thelium, 6 cases from the intestinal mucous membrane, 1 case from the epithelial cells of the bile duct duct and 3 cases from the adrenal cortex.

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[in Japanese]

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From the present knowledge it is clear that the presence of oxygen in culture tubes is absolute necessity in growing the virus as insisted by Dahmen. So, in shake or stab cultures (deep serum agar) the virus develops at a definite distance from the surface and downward, forming a zone of growth or a continuous streak. Moreover, as a further aid in cultivation, tight closing of tubes with rubber stoppers was found to be convenient and satisfactory.
The addition of blood serum to media adapted is an important factor as several investigators have recommended, and it is found that 10 to 15 per cent blood serum was sufficient for luxuriant growth which does not depend upon the kind of blood serum. However, the blood serum. fresh or treated below 70°C. is much better than that heated at a higher temperature. As regards the reaction the suitable hydrogen ion concentration ranges from 6.0 to 8.5, the growth being luxuriant at pH. 7.5. The optimum temperature is 36° to 38°C; the growth ceases below 27°C.
An easy growth is obtainable on 10 per cent serum agar (3% agar). When 0.5 per cent sugar (for example 0.5 per cent glucose, serum agar) was added to the serum agar, the growth was much better. When incubated for a long time the colonies increased in size and showed a thick part in the centre, frequently two or more, taking various irregular forms later on. In general, the development of the colony in the first generation is faint, being easily overlooked, but by generations it becomes to grow with ease. Furthermore, for growing the virus passed through a filter a large quantity of it should be used; otherwise, it is hardly successful. Acid production in the course of development of the virus was recognized by several authors. Our experiments showed serum fuchsin agar with 0.5 per eent glucose, mannose or maltose to be suitable for the purpose, reddening of the medium being very pronounced within 5 or 7 days. When closed in glass tubes and kept at a temperature of 3°-15°C., pleural exudate retains its virulence over six months At 37°-38°C. cultures are destroyed within 50 days, and at a room temperature (5°-32°C.) or a lower temerature (3°-15°C.) they are alive for 70 days. The virus showed less resistance to moist than to dry heat. Of disinfectants, 0.1% chlorate of lime, 1% cresin, lysol and creolin, and sublimate (1:5000) destroyed the virus in a short time, while formalin and carbolic acid showed less destructive action.
As a result of those studies, the following conclusions are drawn:
1. The best medium for growing the virus of contagious pleuro-pneumonia was found to be an agar medium with 10 per cent serum, having a pH of 7.5.
2. A certain quantity of oxygen necessary for the growth of the virus was aimed by closing culture tubes with rubber stoppers.
3. The colonies were not constant in shape as described in several literatures, various stractures being observed in the course of time.
4. For keeping the culture it was found necessary to transfer every one month, vitality being irregular even under the same conditions.
5. The virus showed less resistance to chemical disinfectants. Sublimate 1:5000, 0.1% chlorate of lime, 1% lysol, creolin and cresin as well as 2% carbolic acid may be used for disinfection of infected stable, etc.
6. There was no difference in biological characters between five strains employed.

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