STUDY of the second stage of deglutition by cineradiography has demonstrated for the first time the precise mechanism of this phase of swallowing. Another significant advance is the use of stereoscopic fluoroscopy for more accurate localization of radiopaque foreign bodies in the periphery of the lung, thereby aiding the bronchoesophagologist in their removal. Extension of its use to removal of foreign bodies in the stomach should provide additional help to endoscopists.
HISTOLOGY
By means of electron microscopy the structure of tracheal cilia was studied by Engström.1 The cilia were found to be built up of an axial fibrillar core, ascending from a flask-shaped basal body. Around this bundle of fibrils was a thin fragile envelope, the ciliary sheath. Just above the basal body there was a thin cuticular plate, while from the lower end of the basal body a minute rootlet descended into the epithelial cell. The number of