604 ANATOMY AND PHYSIOLOGY OF THE HORSE'S FOOT. 
than otherwise to the free circulation required in such an 
organ, where local congestion or stagnation of blood is pre- 
vented in ordinary, and often even under extraordinary cir- 
cumstances, by the complexity of arrangement and wonderful 
freedom of communication existing in the various networks. 
From these cursory remarks on the circulation of the blood 
and the disposition of the blood-vessels, I trust I have been 
able to show that a knowledge of this branch of the subject 
is not only interesting, but is of the highest importance with 
regard to the management of the horse's foot in health, and 
its recovery when diseased. In another place we will be able 
to afford some examples of this ; in the mean time, we will 
as briefly refer to another apparatus connected with this ex- 
tremity, which, if not so marvellous in an anatomical or 
physiological point of view, nevertheless demands notice from 
its relations with the organic and sensory functions of the 
foot. I allude to the nervous apparatus of that organ. 
Nerves . — In the region of the horse's foot, there being no 
voluntary muscles to supply with nervous excitability, there 
are no motor nerves or, as they are sometimes named, nerves 
of motion. There is, however, a highly developed system of 
nerves for the transmission of impressions to the brain : 
sensations which are rendered necessary by reason of the 
important part the foot has to play in locomotion. There 
are also present, to a degree commensurate with the exalted 
nutritive processes carried on in this organ, those nerves of 
organic or vegetative life which minister to growth and nutri- 
tion, and which, twining and creeping around the blood-vessels 
to their most delicate ramifications, close as the ivy to the oak, 
maintain these essential acts to a great extent, if not quite, 
independent of the sensory or motor divisions of the nervous 
system. 
The nerves of sensation follow, from the fetlock downwards, 
a direction somewhat similar to that of the arteries and veins. 
One principal cord on each side largely distributes branches 
to the skin and the adjacent tissues ; this branch is loosely 
connected by cellular tissue to the main artery of the foot, 
which lies deeper and in front of it, and the vein, which is 
also in front but more superficial, all three being in advanee 
of the flexor tendons, and situated between them and the 
suspensory ligament of the limb. 
The nerve of each side may be summarily described as a 
large trunk continually sending off branches, the principal 
of which, two or more in number, are directed forwards to 
supply the superficial parts of the extremity in front, fre- 
quently sending out fibres that pass to each other like the 
