DR. BEALE, ON NERVE-FIBRES. 13 
over the fibres and nuclei are much more abundant in con- 
nection with some capillaries than others. They are very 
numerous upon the smallest vessels of the ciliary processes of 
the eye (ox), as well as upon those which are provided with 
muscular fibre-cells, and many are to be found in the con- 
nective tissue upon the free border of the finest vessels. He 
considers that these branches are in part afferent or excitor 
and partly efferent or motor nerves of the vessels. 
The fact of the presence of undoubted nerve-fibres in tissues 
destitute of vessels, and deriving their nutriment from the 
plasma permeating vessels situated perhaps at some distance, 
is another strong argument in favour of the existence of 
afferent nerves, bearing to the vaso-motor branches the same 
relation as the excitor fibres bear to the spinal motor nerves. 
Such fine nerve-fibres are distributed to the cornea of all 
animals, and very fine fibres ramify upon different planes in 
the substance of the proper corneal tissue. From their dis- 
tribution we are justified in assuming that. these fibres are 
not ordinary sensitive fibres, but are nevertheless concerned 
in transmitting impressions of some sort from periphery , 
towards nervous centres, while in certain morbid states they 
are probably instrumental in transmittiug impressions which 
produce the sensation of pain. Ordinarily, these afferent and 
efferent fibres preside over the nutritive process, and it is easy 
to conceive how any alteration in the amount of nutrition 
passing to the tissue must influence, through the nuclei and 
afferent fibres, the ganglia from which the vaso-motor branches 
take their rise. Thus the calibre of the minute arteries may 
be altered by the slightest modification in the supply of pabu- 
lum to the tissues outside capillary vessels dependent upon 
any mechanical or chemical alteration in the tissue whereby 
the activity of the nutritive changes becomes altered. Nor- 
mally, the balance between the quantity of pabulum taken 
up by the tissue and that escaping from the capillaries would 
be maintained through these afferent and efferent fibres, and 
it is easy to understand how any derangement of afferent 
fibres, nerve-centre, or efferent branches would disturb the 
nutritive process. 
Dr. Beale thinks that the rapidity of growth of tissues is 
determined solely by the supply of pabulum, and this supply 
is regulated and equalised by a special system of nerves which 
is, however, connected with the cerebro-spinal system, and 
may influence it, or be influenced by it. He has been led to 
the conclusion that nerves invariably form complete circuits, 
and that there are afferent or excitor nerves and efferent 
or motor nerves presiding over the nutritive processes, which 
may act independently of the cerebro-spinal nerves or centres. 
