THE 



MONTHLY MICROSCOPICAL JOURNAL. 



FEBRUARY 1, 1872. 



I. — On the Belcdion of Nerves to Pigment and other Cells or 

 Elemeniary Parts. By Dr. Lionel S. Beale, M.B., F.R.S., 

 Fellow of the Royal College of Physicians, Physician to King's 

 College Hospital. 



(Iteud hrfore the Iioyal Microscopical Society, Dec. 6, 1871.) 



Plate VI. 



The tendency of opinion in these days seems to be in favour of the 

 conclusion that the finest branches of the nerve fibres come into 

 structural relation with the active elements of other tissues. Many 

 profess to have traced nerves into epithelial cells. A number of 

 authorities agree in asserting that the ultimate nerve fibres come 

 into actual contact with, and are probably in very close relation with 

 the contractile tissue of striped muscle. Not a few assert that the 

 nerve fibre may be traced into the nucleus of unstriped muscular 

 tissue. Kiihne concluded that the nerve fibrils were continuous 

 with the prolongations of the connective-tissue corpuscles of the 

 cornea, and M. Gr. Pouchet published a paper in the December 

 number of the Journal with the object of convincing us that fine 

 nerve fibres were continuous with — in fact ended in the pigment 

 cells (chromoblasts) of the skin of fishes. 



Upon' the other hand, my observations have led me to the 

 general inference that in no case do the finest terminal ramifications 

 of the nerve fibres end in the manner described ; and whatever may 

 be the nature of the influence produced by the nerves upon the 

 structure, and the action of various tissues and organs, I do not 

 think that it is dependent upon continuity of substance between 

 the nerve and the tissue affected. 



From what I have seen I feel confident that at least in many 

 cases the contraction of a muscular fibrilla depends upon a change 

 in the nerve which runs near to it, but is distinctly separated from 

 it — upon such a change as a varying intensity in the electrical 

 current traversing the nerve fibre might occasion ; and when con- 

 traction of protoplasm (bioplasm) follows upon irritation of nerve 

 fibres, I believe the result is also due to the same circumstance, and 



VOL. VII. E 



