We have reported previously on the morphology of the enamel-dentin border of maxillary median incisor in this journal (Vol. 73, No. 3, 1965). The present article is the description on maxillary canine as the second chapter of our work.

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Electromyographic recordings of many muscles in four limbs while man or dog was walking were made using surface electrode technique. The results are summarized and illustrated in Fig. 4 (dog) and in Fig. 6 (man). Electromyograms got by using electroencephalograph while man was walking are also shown in Fig. 7 and 8.
The activity duration of retractors is longer than that of protractors except leg muscles. Some discussion was made on the complete or incomplete reciprocity of activities in antagonistic muscles, in right and left muscles of the same name, and also on the relation of the activities of proximal and distal muscles in the same limb. Time sequence of the activities of protractors or retractors in four limbs is consistent with the backward cross type (Fig. 5) in dog, and with the forward cross type (Fig. 9) in man. Therefore the forward cross type is said to be the walking type frequently observed in primates including man.
The deafferentation of fore limbs or hind limbs was made in dog, and its effect on walk was observed. By the deafferentation of both hind limbs, the supporting ability in hind limbs was depressed, and some abnormal posture of hind limbs as well as the temporal duplication of the antagonistic muscular activities was observed. But recovery was rapid and without change in walking type. By the deafferentation of one hind limb, reciprocal movement of hind limbs in walk lost its balance. Thus supporting duration of intact hind limb became longer and that of deafferentated hind limb became shorter. First step in walk was begun with the deafferentated hind limb. Recovery was rapid. Walking type was the backward cross type as before.
By the deafferentation of both fore limbs, the supporting ability in fore limbs was depressed, and this caused a severe obstacle in walking. Besides, the fore limbs could not move in good timing with the movements of hind limbs or the coordination of movements between fore limbs and hind limbs was lost, and the protracted fore limb was not placed on the ground properly; the dog frequently tumbled down in walk. Recovery was slow. The walking type when the dog walked without tumble was the backward cross type as before. From these results, the sensory impulses from the fore limbs are thought to be more important in walk than those from the hind limbs. The main reason may lie in the fact that the body weight of the dog is largely supported by the fore limbs.

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[in Japanese]

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Global EMG of various muscles in approximately isometric-isotonic contractions were recorded before and during the cooling of the muscles, and changes in frequency components were studied using an automatic frequency analyzing integrator.
Skin temperature near the recording electrodes were used as a measure of the degree of cooling.
The frequency spectrum showed remarkable lowering when the muscle was cooled. The degree of spectrum changes were reversible and related to the temperature.

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