PACIXIAX BODIES. 



149 



Fig. 102. 



shape, nearly -j^l^ of an inch long, and jr^-^ of an inch tliick. AYithin 

 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, with perhaps 

 some horizontally 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 retaining 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 papillae which usually include no vessels. It 

 may be here observed that loops of nerves are sometimes seen in papillfe 

 without touch-bodies, but probably they belong to a nerve on its way 

 to end in the corpuscle of a neighbouring papilla. 



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 ascer- 

 tained that each of these l)odies 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 sti'uc- 

 ture, and his account of them seems not to have 

 attracted much notice. In more recent times, 

 their existence was again pointed out by Cru- 

 veilhier and other French anatomists, as well as 

 by 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 were 

 followed up by Heule and Kulliker,f who named 

 the corpuscles after the Italian savant ; and to 

 their memoir, as well as to more recent papers,:}; 

 the reader is referred for details that cannot be 

 conveniently introduced here. 



The little bodies in question (fig. 102) are, as 

 already said, attached in numbers to the branches 

 of the nerves of the hand and foot, and here 

 and there one or two are found on other cuta- 

 neous nerves. They have been discovered also 

 within the abdomen on the nerves of the solar 

 plexus, and they are nowhere more distinctly seen or more conveniently 

 obtained for examination, than in the mesentery of the cat, between 



* Abr. Vatei-, Diss, tie Cousensu Partium Corix bum. ; Vitemb. 1741, (recus. in Halleri 

 Disp. Anat. Select, torn. ii.). Ejiisd. Museum Aiiatomicum ; Helmst. 1750. 



t Ueber die Pacinischen Korperchen ; Zurich, 1844. 



t Bowman, Cyclop, of Anat. W. Krause, Anat. Untersuchungen ; Hannover, 1861, 

 and Zeits. f. rat. Med. xvii. 1865. T. W. Engelinann, Zeits. f. Wiss. Zool. xiii. 1863. 

 Michelson, Schultze's Archiv, v. 1869. Axel Key and Ketzius, Schultze's Archiv, ix. 

 1873. 



Fi 



g. 102. — A Neuve 

 OP THE Middle 

 FisGER, WITH Paci- 

 nian Bodies at- 

 tached. Natural 

 size (after Henle 

 and Kolliker). 



