370 THE SOLIDS. 



ber; the nerve tube, immediately on its entrance into this 

 chamber, loses its double and denned border, in consequence, 

 it is presumed, of the absence of the white substance of 

 Schwann. (Plate XLVLj^$. 2, 3.) 



Such is a brief and general description of the Pacinian 

 body ; one or two other points of a less evident character still 

 remain to be noticed. It has been stated that the capsules 

 contain elongated nuclei in their parietes, that they are formed 

 of fibrous tissue, and that the spaces between them have no 

 communication with each other: if the outer and larger capsules 

 be carefully examined it will frequently be observed that they 

 present a double edge separated by a faint interval, and con- 

 veying the impression that each capsule is made up of two 

 distinct membranes : it is in this interval that the nuclei are 

 lodged : that the inter-capsukr spaces do not communicate 

 with each other is proved by the fact that when the outer 

 capsules are pierced "through, the fluid escapes only from the 

 spaces which have been opened into ; if the whole of the cap- 

 sules have been divided the entire corpuscle immediately col- 

 lapses. (It is a curious fact that a Pacinian body allowed to 

 dry up does not again absorb fluid and expand to its natural 

 size.) It has also been observed that the capsules are united 

 to each other at the proximate extremity of the Pacioian 

 body along the sides of the canal already described : according 

 to Pacini they are also bound together at the distal end by a 

 band of fibrous tissue, which he calls the " intercapsular liga- 

 ment : " the existence of this ligament has been denied by 

 Henle and Koelliker.* Todd and Bowman do not deny its 

 existence, but state that they have seldom seen it reach the 

 surface of the corpuscle, f 



Pacinian bodies not unfrequently present varieties of form 

 and structure : it is possible that many of these admit of ex- 

 planation on the supposition that in some instances they are 

 multiplied by self -division : thus sometimes the distal end of 



* Ueber die Pacinisclien Korperchen an den Nerven des Menschen 

 und der Saugethiere, Zurich, 1844. 



f Physiological Anatomy, vol. i. p. 397. 



