GO The Nerves of Capillary Vessels and their 
The arrangement represented we shall find will act as a self- 
regulating mechanism of the most perfect kind. Suppose for a 
Diagram to show self-regulating mechanism connected with the minute arteries 
and capillaries, a, artery with muscular fibre cells ; the dark lines show its 
diameter when dilated, b, small vein, c, capillary network. Over No. 1 the 
capillaries are dilated, and over No. 2 they are contracted, d is a ganglion cell 
with at least two sets of nerve fibres connected with it, one of which, e, divides 
and subdivides, giving off nerve fibres which are distributed to the artery a, 
while the other, /, is continuous with the plexus of nerve fibres ramifying close 
to the capillary vessels. Nerve fibres are also distributed to the small vein, b, 
but these are not represented in the drawing. The bioplasm of the vessels and 
nerve fibres is represented. 
moment a tissue is receiving more nutriment than it appropriates, 
the capillary nerve fibre will be at once disturbed, a change instantly 
transmitted to the nerve centre, and the afferent nerves distributed 
to the artery participating, will cause the muscular fibres to contract. 
The arterial tube is thus narrowed, and less blood consequently 
sent to the tissue. In an opposite state the phenomena would be 
