442 



THE TISSUES. 



is as 10 to from 1 to 3.3. (Bidder and Volkmann.) The nerves of bone 

 contain in their trunks J of coarse, and f of fine fibres; while 

 those of the articulations, tendons, and membranes, exhibit a great 

 preponderance of fine fibres. (Kolliker.) 



4. The manner in which the motor nerve-fibres terminate (by 

 divisions, &c.), has already been described (p. 416). The termina- 

 tions of the sensory fibres in loops, divisions, and free terminations, 

 will be described in the chapter on the skin. (Chap. XI.) 



A peculiar form of termination of the spinal nerves, is however 

 to be noticed here ; viz., that in the Pacinian bodies. 1 These organs 



Fig. 286. 



A. Nerve from the finger, natural size ; showing the Pacinian corpuscles. B. Ditto, magnified 2 

 diameters ; showing their different size and shape, c. Single corpuscle, highly magnified, showing 

 a, its peduncle, &, its contained nerve-fibre ; c, outer layers, and d, inner layers of the capsule ; e, 

 nerve-fibre become pale in its passage through the interior of the corpuscle ; /, its subdivision and 

 termination. 



are of an elliptical or py riform shape, of a whitish 'transparent color, 

 with white streaks internally, and are from ^ to ^ of an inch in 

 diameter. They are constantly found on the cutaneous nerves of 

 the palm of the hand, and the sole of the foot, in the subcutaneous 

 areolar tissue, and most numerously on the fingers and toes, parti- 

 cularly on the third phalanx. There are about 600 in the hand, 

 and not quite so many in the foot. (Fig. 286.) They are always 



1 From Pacini, who discovered them in 1840. 



