4 Transactions of the 



II. — The Nerves of Cajnllary Vessels and their Prdbahle Action 

 in Health and Disease. By Dr. Lionel S. Beale, F.R.S., 

 Fellow of the Eoyal College of Physicians, Physician to 

 King's College Hospital. 

 (^Read lefore the Eoyal Microscopical Society, Dec. 6, 1871.) 

 Part I. — Anatomical Investigation. 



Plates III., IV., and V. 



When studying the distribution of nerves to striped muscle in 

 I860,* I had seen nerves lying close to capillary vessels, and 

 dui'ing the next two years obtained several preparations from the 

 frog, toad, and newt, in which pale dehcate nerve fibres, which had 

 been followed from trunks containing dark-bordered nerve fibres, 

 were discovered running by the side of almost every capillary vessel 

 ramifying over an extensive area of tissue. In 1863 some 

 drawings were published,! and in my Croonian lecture to the 

 Fellows of the Eoyal Society in May, 1865, the distribution of 

 nerves to capillary vessels was briefly described, and the function 

 performed by them discussed. Although I have incidentally 

 referred to the fact in several lectures and papers published since 

 this period, I have not collected my observations, nor until now 

 have I entered into the matter so fully as it deserves. The subject 

 appears, however, to have been almost completely passed over by 

 other anatomical observers in this country and on the Continent.^ 



* " On the Distribution of Nerves to the Elementary Fibres of Striped 

 Muscle," ' Phil. Trans.,' June, ISfiO. 



t " On the Structure and Formation of the so-called Apolar, Unipolar, and 

 Bipolar Nerve Cells of the Frog." May 7, 18G3. ' Phil. Trans.' : Part II., 1863. 

 Published separately. Churchill, 1864. 



X It is not a little remarkable that the opinion should, until very recently, 

 have been entertained that all the arteries even are not siipplied by nerves, and 

 that the contraction of the unstriped muscular fibre is induced independently of 

 nervous influence. It is some years since I was led to the conclusion that all 

 forms of muscle are supplied by nerve fibres, and I am of opinion that every 

 small artery possesses nervous supply even iu those instances in which I have 

 myself failed up to this time to demonstrate nerves. I do not think, however, 

 that all capillaries have nerve fibres distributed to them, and it is quite certain 

 that, as in the case of different tissues, the number of nerve fibres over a given 

 area varies greatly. KiJlliker made the remarkable observation that some of 

 the arteries are destitute of nerves, and that the walls of arteries are not in 

 such need of nerves as is usually supposed. Eberth, in Strieker's ' Handbook,' 

 just published, says, " with the exception of the capillaries " the presence of nerves 

 has been demonstrated in (upon ? L. S. B.) all vessels, but he remarks that he has 

 not been able to convince himself of the precise mode in which they terminate, 

 especially as regards the muscular fibres of the arteries and veins. 



After this paper had been read on December 6th, Dr. Klein showed me some 

 plates to illustrate a memoir by him upon the same subject, which will appear in 

 the January number of the ' Quarterly Journal of IMicroscopical Science.' His 

 specimens were prepared by the gold process, and give a difterent idea of tlie 

 distribution of the nerves to that aiforded by mine, some of which are ten years old. 

 My own conclusions on the ultimate distril)ution of nerve fibres were formed 

 several years ago, at a time when terminal nerve networks were denied in 



