No man can determine the physiological condition without recognition of vivid phenomena going in the inside of the body, even in mice and other small animals. It is the minimal demand of biological investigation to conceive the condition of heart beat, respiratory movement, blood pressure and body temperature. Then, if they are shown objectively by some proper methods, it is presumed that a prompt advancement may be expected in the wide range of investigation using the aniaml.
Nevertheless, especially in mice, the observatory method of the above-mentioned factors showing fundamental physiological condition has scarcely been considered, because the technique concerning the fixation and operation of animal mainly were seemed to be very difficult.
Among the present studies, in the first place, the procedures connected with the simultaneous observation and recording of the factors were discussed in their details.
As a consequence, it was clarified that observation of the heart beat and the body temperature were comparatively easy, but the measure for observing the blood pressure and the respiratory movement contained various difficulties. Therefore, several particular devices have been done about these two factors, because the fitted methods should be newly established and they must have an extensive application in spite of a rather difficulty in the technique. SUZUTA and OKUGI's direct method for measurement of the carotid arterial blood pressure was modified in some details: in the present method, preparation for the cannulation was performed by the electroshock, substituted for drug anesthesia and then, holding of the body with the aid of clay, modification of the cannula for lightening of the weight and dulling of the point of needle avoiding damage of the artery was examined.
For calculation of the respiratory rate, the EMG of the diaphragm and the pneumotachogram using tracheal cannula and various shaped masks were tested. The results denoted that the glass mask produced by the authors was the most suitable.
Finally the treatment and expression of the values obtained was discussed. The normal standard zone, in particular, needed for comparative discussion hereafter was established, presupposing the procedure hitherto described. In order to examine usefulness of the zone, furthermore, several experiments concerning the effect of medical drugs on mice were performed.
In the results, the authors presumed that these new methods may be able to be applied extensively in clinicophysiological or pharmacological studies using the mice as materials.

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This experiment was made to see whether weight ratios of organs-body and relative sizes of bones to skull length are influenced by the planes of nutrition or not.
Experimental animals were male mice of two inbred strains dd, rr and their reciprocal hybrids F₁ dr, rd. They were, within 5 days after their birth, divided into two groups, and were fed respectively with high and low planes up to 60 days of age. The results are as follows:
1. Weight ratios of organs-body were larger in low plane of nutrition than in high one. This seems to be due to the reason that insufficiency of fat and protein in low plane restrains the increase of these in the body, especially in the unmeasured organs, and it naturally restrains the growth of body weight which was used as a denominator.
As for these ratios, strain difference was found between dd and rr. However, no difference was noted between the inbred and its hybrid or between dr and rd.
2. As for relative sizes of partial bones in skull length, few differences were found between high plane of nutrition and low one. This seems to be due to the following reasons; first, these partial bones belong to the same skull as skull length, second, skull completes its growth fairly at an early stage of development, and its growth was scarcely affected by such nutritional conditions as this experiment.
3. On the contrary, length of head and trunk, tail length, femoral length and tibial length continue to grow comparatively later. So these are more affected by nutritional conditions than skull length is. Results that relative sizes of these bones to skull length were larger in high plane than in low one will be explained by the above reason.

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A strain of microphthalmic mice was established from progeny of the X-ray irradiated DD-strain of mice (KASHIWABARA et. al., 1957, 1958) . In this strain, Irregular occlusion of incisors has been occured frequently.
Detailed morphological observation on skull revealed that Fusions of frontal and parietal bones, Bent of fronto-parietal bones, and Bent of nasal bones, occured as frequently as the occurence of Irregular occlusion of incisors. The percentage in the occurences of Fusions of frontal and parietal bones was 77.5%; Bent of f ronto-parietal bones, 32.6%; and Bent of nasal bones, 41.9%. The percentage in the occurences of Irregular occlusion of incisors was 14.7% (Table 1) .
The correlation between the asymmetrical Fusions of frontal and parietal bones and the occurences of Bent of the fronto-parietal bones was very high. The correlation coefficient was 0.892±0.062 (Table 2) . There was no correlation between occurence of Bent of the fronto-parietal bones and Bent of the nasal bones (Table 3) . It was observed that as the direction of Bent of fronto-parietal bones and Bent of nasal bones coincided, the occurence and manifestation of Irregular occlusion of incisores increased (Table 4) .
These facts would suggest that Irregular occlusion of incisores would be caused by Bent of frontoparietal bones and Bent of nasal bones. Furthermore, it would be indicative that Bent of f ronto-parietal bones would be caused by the occurence of asymmetrical Fusions of frontal and parietal bones.

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