1951 年 2 巻 p. 177-185
Factors governing individual differences of temperature reaction to cold found by Lewis were studied by estimating reaction index devised in the first part of this study. Main results obtained are as follows:
1. The reaction was found even a few days after birth and developed rapidly with lapse of days. The high reactivity in childhood was lessened in puberty and again it rose in young adult, after which it decreased gradually with the progress of age.
2. A female adult seemed to show a little lower reactivity than a male.
3. Native countries and racial specificity were proved to have an intimate relation with the reactivity, and a main factor of the influences was deduced to be the effect of training to cold.
4. The Orochons were found to have the highest reactivity among all nations in Manchuria, and thus protecting themselves from frost-bite, adapted to their nomadic life in a cold country. The reactivity of Japanese adults recently came to Manchuria was the lowest of all the natives, while that of Japanese children was about the same with those of the native (the Mongols and the Chinese) children.
5. A validity of training effect reported by Takahashi was ascertained, and it was proved that the effect was more remarkable on the youth than on the adult.
6. Subjects of low reactivity were proved to show frequently high sympathetic tonus. Thus the tonus of autonomic nervous system had an intimate bearing with the reactivity.
7. Main internal factors causing individual differences of the reaction were presumed to be differences of the following three: the morphological constitution, especially of blood vessels, the nervous control (activities) and other physiological properties of the skin. The experimental results mentioned above were explained from this point of view.