ANATOMICAL OBSERVATIONS ON THE MUSCULI SUPRAHYOIDEI AND APPARATUS HYOIDEUS WITH SPECIAL REFERENCE TO THE MUSCULUS JUGULOHYOIDEUS AND OS STYLOHYOIDEUM OF THE MOUSE, HAMSTER AND RAT

The musculi suprahyoidei and apparatus hyoideus were investigated usin g a combination of gross dissection and histological techniques in the mouse, hamster and rat. The new findings with regard to these are as follows: (1) the musculus jugulohyoideus, which runs from the processu s jugularis to the os stylohyoideum, exists in the mouse and hamster, but is absent in the rat; (2) the m. jugulohyoideus is innervated with the ramus jugulohyoideus from the nervus facialis; (3) the os stylohy oideum and the os tympanohyoideum exist on the lateral surface of the bulla tympanica in the mouse, hamster and rat, and (4) four kinds of m uscle (m. stylohyoideus, m. styloglossus, m. stylopharyngeus, m. jugul ohyoideus) attach to the os stylohyoideum in the mouse and hamster; ho wever, no muscles attach to the os stylohyoideum in the rat.