PACINIAN CORPUSCLES. 



341 



Certain corpuscles which are found in the bill of some water-birds, exhibit so obviously a 

 transition between the simple corpuscles of Herbst and the complex corpuscles of Pacini 

 immediately to be described, that they may be especially mentioned here. These, which are 

 sometimes named after the anatomists who first described them, the rorjuiscle* of Key and 

 Jtetzhtg (fig. 401), dift'er from the corpuscles of Herbst in having a capsule, composed of a 

 large number of closely-arranged lamellas, similar to those of the inner or denser part of the 



Fig. 400. MIDDLE PART OF A HERBST CORPUSCLE OF THE SPARROW. OSMIC PREPARATION. 



(W. Krause.) =f. 



h, outer longitudinal fibrous layer ; r, felt work of transverse fibres ; i, core, with two rows of 

 nuclei ; t, axis-cylinder. 



Fig. 401. KEY-RETZIUS CORPUSCLE IN OPTICAL LONGITUDINAL SECTION. BICHROMATE PREPARATION. 



(W. Krause.) *'{>. 



h, outer layer ; c, i, concentric lamellae of capsule ; n, terminal nerve-fibre. 



Pacinian corpuscle, outside which is a single strong layer of longitudinally disposed fibrous 

 tissue. The inner lamellte are largely composed of circular or transverse fibres, but these lack 

 the brownish tint of the fibres of the inner lamella of the Herbst corpuscle, nor do they exhibit 

 the intra-lamellar fluid which is characteristic of most of the lamellas of the Pacinian 

 corpuscle. 



Corpuscles of Vater or 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 chat each of these bodies receives a nervous fibre which 

 terminates within it. The objects referred to were described and figured by Vater 

 (1741), as attached to the digital nerves, but he did not examine into their struc- 

 ture, and his account of them seems not to have attracted much notice. In more 

 recent times, their existence was again pointed out by Cruveilhier and other French 

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

 gave an account of the internal structure of these curious bodies, and clearly demon- 

 strated their essential connection with nerve-fibres. The researches of Pacini were 

 followed up by Henle and Kolliker, who named the corpuscles after him ; and the 

 Pacinian corpuscles have since been the subject of numerous papers, to which the 



