150 



:XEIIY0US TISSUE. 



the layers of which they exist abundantly. They have been found on 

 the pudic nerves in the gians penis and bulb of the urethra, on the 

 intercostal nerves, sacral plexus, cutaneous nerves of the upper arm 

 and neck, and on the iuiVaorbital nerve. Lately they have been 

 recoo'uised on the periosteal nerves, and, in considerable numbers, 

 on the nerves of the joints. They are found in individuals of all ages. 

 The figure of these corpuscles is oval, somewhat like that of a grain of 

 Avheat, — regularly oval in the cat, but mostly curved or reniform in 

 man, and sometimes a good deal distorted. Their mean size in the 

 adult is from y'-th to y^gth of an inch long, and from ^^^th to -j^th of 

 an inch broad. They have a whitish, opaline aspect : in the cat's 

 mesentery they are usually more transparent, and then a white line 

 may be distinguished in the centre. A slender stalk or peduncle 

 attaches the coi'puscle to the branch of nerve with which it is connected. 

 The peduncle contains a single meduUated nerve-fibre ensheathed in 



Fig. 103. 



Fig. 103. — A, Magnified View of a Pacinian Body from the Mesentery of a Cat 

 (from a drawing by Professor Marshall), showing the lamellar structure, the capsules with 

 their nuclei (the inner and closer series of capsules apiieariug darker in the figure) the 

 nerve-fibre x^assing along the peduncle, and penetrating the capsules to reach the core iu 

 the central cavity, where it loses its strong, dark outline, and terminates by an irregular 

 knob at the distal and here dilated end of the cavity. Connective tissue (neurilemma 

 or perineurium) and blood-vessels are represented in the peduncle, and tortuous capillaries 

 are seen running up among the capsules, b and c represent the termination of the nerve 

 with the distal end of the central cavity and adjoining capsules, to illustrate varieties of 

 arrangement. In b the fibre, as well as the core and adjoining capsules, is bifurcated. 



