抄録
Ten larynges of hens were studied morphologically under an operation microscope, with a special reference to the evolutional stage of the laryngeal structures. The results of the present investigation were compared with results of previous studies on the same topic by other investigators and by ourselves.
The posterior cricoarytenoid muscle of mammal has been regarded as a derivative of the dilator fibers of the primitive larynx. The results of the present study, however, suggested that it is derived from the posterior laryngeal constrictor in the primitive larynx. In the present study it was also suggested that the arytenoid muscle is originated from muscular tissue which appears adjuscent to the lateral cartilage in a certain stage of evolution, although the arytenoid muscle has been considered a derivative of the posterior laryngeal constrictor of the primitive larynx.
In contrast to mammalian larynges, the glottis is open during phonation in hen's larynx. Most laryngeal muscles in the hen are abductors. The arytenoid muscle only is the adductor. Since the sound generator of the hen is the syrinx, it is presumed that there are neural pathways which functionally connect the larynx and the syrinx very closely.
