Muscle spindles in the intrinsic and extrinsic muscles of the Rhesus monkey's (Macaca mulatta) tongue

Neuromuscular spindles were searched for in the intrinsic and extrinsic muscles of the rhesus monkey's tongue. Transverse, horizontal and parasagittal sections were obtained from the tongues of three animals and stained with the Weigert‐van Gieson technique. The results showed that spindles were distributed in all of the intrinsic muscles as well as in certain of the extrinsic muscles. The potential significance of these findings is discussed in relation to the feedback pattern derived from the lingual spindles in response to tongue activity.