Histological and anatomical studies on the temporal bones in Homo (Japanese): Part III. The fine structure in pyramidal apex of petrous bone, especialy views about the conditions of the dehiscence@@@第三篇 顳〓骨錐體尖端部ノ微細構造殊ニ錐體尖端部ニ於ケル骨罅隙ニ就テ