Some Observations upon the Peripheral Nervous System of the Hagfish,Myxine Glutinosa

Abstract

Observations are described upon the innervation of striated muscles, the innervation of the slime glands, and the subcutaneous innervation in the hagfish, Myxine glutinosa L. It is shown that the two types of striated muscle fibre receive different types of motor innervation. Presumed sensory endings are described from above the striated muscle fibres of the ventral part of the body, and are similar to those endings near to the dorsal root ganglia whichcan be traced to their cells of origin within the ganglia. It is suggested that these endings are proprioceptive in function. Other endings within the outer edge of the myosepta are described, which may possibly also have a proprioceptive function. A rich plexus of neurons is described upon the capsule of the slime glands, and these neurons, like those of the subcutaneous plexus, receive pericellular terminations from the axons of central cells. It is suggested that they are motor to smooth muscle fibres, in the slime-gland plexus being related to the expulsion of slime (together with the action of striated muscle fibres), and in the subcutaneous plexus playing some role in the control of the venous blood in the subcutaneous sinuses.