1. The chimpanzee has well-developed aryepiglottic folds which allows him to vocalize not only upon expiration but also upon inspiration, which for man is strenuous and unpleasant.

2. The tumours mainly involves the aryepiglottic folds, the ventricular folds or extending to the pyriform fossa, uncommon being subglottic.

3. Supraglottic injuries in two cases including c fractures of the epiglottis in 2 and associated with a laceration of the aryepiglottic folds and the hypopharynx.

4. Posterior pharyngeal carcinoma (14 cases) usually invaded pyriform sinus (100%), aryepiglottic fold (92.9%), postcricoid region (71.4%), prevertebral fascia (71.4%) and esophagus (64.3%).

5. Results The primary sites of these 4 cases were later discovered, 2 in the aryepiglottic fold, 1 in faucial tonsil and 1 in the skin of the head, respectively.