136 



PEEIPHERAL NERVE TERMINATIONS 



They are especially numerous in the extrinsic muscles of the 

 tongue, in the small muscles of the hand and foot, and in the 

 intercostal muscles (Huber*). 



A muscle spindle contains from five to twenty striated muscle 

 fibres of small size, and an almost equal number of nerve fibres. 

 The whole is inclosed within a connective tissue capsule of con- 

 siderable thickness. The bundle of intrafusal muscle fibres is 

 again surrounded by a delicate axial sheath of connective tissue 

 which is united to the capsule by bands of fine fibrous tissue 



FIG. 136. MIDDLE THIRD OF A TERMINAL PLAQUE IN THE MUSCLE SPINDLE OF AN 



ADULT CAT. 



A, rings ; F, dendritic branchings ; S, spirals. Chloride of gold preparation. Highly 

 magnified. (After Ruffini.) 



which span the broad periaxial lymphatic space. The larger of 

 these fibrous bands support the nerve fibres, on their way to 

 the intrafusal muscle cells, together with several small blood 

 vessels. 



The muscle spindles form long fusiform bodies whose muscle 

 fibres at the pole of the spindle may be connected with the ten- 

 don, or they may join other muscle fibre bundles. The muscle 

 spindles are usually found in the fibrous septa of the peri- 

 mysium. 



* Am. J. of Anat., 1902. 



