Muscle spindles in the digastric muscle of the rabbit.

The digastric muscle of the rabbit was studied for the presence of muscle spindles. One of the 19 adult digastric muscles we examined contained in excess of 12 spindles scattered throughout the belly. No spindles were found in the contralateral muscle, or in any of the digastric muscles from other animals. Although jaw depressor muscles of most mammals contain few, if any, muscle spindles, their occasional presence suggests that these muscles have a potential for spindle formation.