clii 



NERVOUS SYSTEM. 



J~ of an inch thick. Within is a core of soft, transparent, homogeneous substance, 

 with sparsely imbedded granules; outside, a capsule of connective tissue, with 

 oblong nuclei directed transversely to the axis (and rendered more conspicuous 

 by acetic acid or coloration with carmine), which, -together perhaps with some hori- 

 zontally wound fibres, give the corpuscle somewhat the appearance of a miniature 

 fir-cone. One, two, or even more nerve-fibres, run to the corpuscle, and proceeding 

 straight, or with serpentine windings, approach the summit, up to this point retain- 

 ing their dark borders ; they then pass into the core, and, so far as can be seen, end 

 as fine pale fibres. The touch-corpuscles are found in the skin of the hand and foot, 

 and one or two other parts, where they are inclosed in certain of the cutaneous 

 papillas, which usually include no vessels. It may be here observed that loops of nerves 

 are sometimes seen in papillae without touch-bodies, but probably they belong to a 

 nerve on its way to end in the corpuscle of a neighbouring papilla. 



Fig. LXXXV1II. 



Pig. LXXXVIIT. PAPILLA PROM THE SKIN OP THE HAND, FREED FROM THE CUTICLE 

 AND EXHIBITING THE TACTILE CORPUSCLES. MAGNIFIED 350 DIAMETERS. 



A. Simple papilla with four nerve-fibres, a, Tactile corpuscle ; b, nerves. B. Papilla 

 treated with acetic acid ; a, cortical layer with cells and fine elastic filaments ; 6, tactile 

 corpuscle with transverse nuclei ; c, entering nerve with neurilemma or perineurium ; 

 d, nerve-fibres winding round the corpuscle, c. Papilla viewed from above so as to appear 

 as a cross section, a, cortical layer ; 6, nerve-fibre ; c, sheath of the tactile corpuscle 

 containing nuclei ; d, core (after Kolliker). 



c. Pacinian bodies. In dissecting the nerves of the hand and foot, certain small 

 oval bodies like little seeds, are found attached to their branches as they pass through 

 the subcutaneous fat on their way to the skin ; and it has been ascertained that each 

 of these bodies receives a nervous fibre which terminates within it. The objects 

 referred to were more than a century ago described and figured by Vater,* as 

 attached to the digital nerves, but he did not examine into their structure, and his 

 account of them seems not to have attracted much notice. Within the last few years, 

 their existence has been again pointed out by Cruveilhier and other French anato- 

 mists, as well as by Professor Pacini of Pisa, who appears to be the first writer that 

 has given an account of the internal structure of these curious bodies, and clearly 

 demonstrated their essential connection with the nervous fibres. The researches of 

 Pacini have been followed up by Henle and Kolliker, f who named the corpuscles 

 after the Italian savant ; and to their memoir, as well as to the article " Pacinian 

 Bodies/' by Mr. Bowman, in the " Cyclopaedia of Anatomy," and to more recent 



* Abr. Vater, Diss. de Consensu Partium Corp. hum. ; Vitemb. 1741, (recus. in 

 Halleri Disp. Anat. Select, torn, ii.) Ejusd. Museum Anatomicum ; Helmst. 1750. 

 t Ueber die Pacinischen Korperchen ; Zurich, 1844, 



