The mice studied were of male and female C 57 BL/6, male and female CBA, male and female CF #1, male dd/YF and male ICR/JCL at the age of fifty days. Fifty mice were choiced for each sex and each strain from the data of repeated experiments for various purposes, according to the age, sex, strain and housing condition in our laboratory.
The distribution of body weight at the tenth day after putting into an individual cage from other cages showed a single or more lines on the logarithmic probability paper. The distribution of the mean square successive difference induced from the daily body weight for ten days in the individual cage, showed three lines on the logarithmic probabiity paper, except two lines for female C 57BL/6mice. The mean square successive difference expressing the physiological state of individual mouse, those three lines showed that the population of mice was divided into three groups of mice with three types of phisiological states probably due to long-conditioning stimulus. These types showed different responses against whole body irradiation. Studying on the mean square successive difference induced from body weight, it was noticed that the effect of removing mice from a cage to another one remained for ten days at least, since the value was unstable till the ten days.
Figure 1 Distribution of body weight in various strains and sexes of mice. Mice were housed separatly in an individual cage for ten days and weighed at the tenth day.
Figure 2 Distribution of mean square successive difference (δ2) induced from body weight of various strains and sexes.
Mice were housed separately in an individual cage for ten days and δ2 was calculated from the daily body weights for ten days.
Figure 3 Changes in body weight and in mean square successive difference induced from body weight in every successive two days after putting the mouse into an individual cage. Mice C57BL/6 mice at the age of fifty days were weighed at 10: 00 a. m. for ten days in the individual cage.
Table 1 Survival at 30 days after 400 R whole body X-ray irradiation. Mice dd/YF mice were irradiated at tenth day after putting into an individual cage separately.