THE SUMMERING OF HUNTERS. 133 



When the muscle contracts, each fibre or rod 

 shortens and thickens, and as the muscle relaxes 

 and lengthens the fibres also relax and lengthen, so 

 that the chamiels between the fibres, which we saw 

 were occupied by the absorbent vessels, are alter- 

 nately widened out and closely pressed in, and so a 

 suction process is established. If a horse walks he 

 lifts his foot perhaps, once a second, and therefore 

 the muscles at the back of his leg — foreleg, for 

 example— contract and lengthen once a second, or 

 in other words, the suction pump acts once a second. 

 To illustrate this suction process; in the fall of the 

 year take a horse with " filled legs " — that is to say 

 legs whose tissues are saturated ^'\i\ifiuid from the 

 blood vessels w^hich has settled in his legs because 

 he has been standing still in his stable, and this 

 fluid, for reasons we shall explain, in the autumn 

 has been unable to find its way back into the veins. 

 This fluid in the " filled legs" is only acted upon 

 by one force, gravity. Its weight causes it to settle 

 to the lowest parts. But now put the suction force 

 in operation by walking the horse out for half an 

 hour and then see. He comes in with his legs 

 " fine" once more. Some muscles besides the heart 

 are always working from the animal's birth to his 

 death — the diaphragm or midrif for example. 



We shall not apologise for taking the reader 

 seemingly so far away from the subject ; first, 

 because thousands of horses and cattle— aye, and 

 human beings too — are yearly lost or ruined for 



