620 A MANUAL OF VETERINARY PHYSIOLOGY 



. The Walk. 



This pace is relatively slow ; an ordinary horse walks about 

 four miles an hour, and it would seem that, considering each limb 

 can be distinctly observed, its movements would be easy to 

 follow. As a matter of fact, to watch them is bewildering. 

 The walk begins from a fore-leg. If a horse from rest begins 

 to walk, one or the other fore-legs will be found the first to 

 advance ; there is no special choice shown as to whether it will 

 be a near or an off leg, though an animal may time after time 

 start with the same limb. This is not the generally accepted 

 opinion outside the veterinary world. Muybridge himself says : 



1 When a horse is standing with the weight of the body equitably 

 distributed over his fore-legs, and under these conditions commences 

 to walk, the initiatory movement will invariably be made with a 

 hind-foot.' 



Borelli, who wrote on animal mechanism towards the end of 

 the seventeenth century, described the walk as beginning with a 

 hind-foot, but this has never been accepted by any veterinary 

 writer. Percivall and Gamgee especially attacked it. Hayes 

 says : ' As a rule a horse begins the walk with a fore-leg.' This 

 suggests he has seen a hind-leg initiate the movement — in fact, 

 he describes the sequence of limb movements which occur when 

 a hind-leg is the first to start. It seems a remarkable fact, when 

 all the most difficult questions connected with locomotion are 

 settled, that the simple one discussed above is not satisfactorily 

 determined. In consequence of the opinion of Muybridge we 

 are unwilling to deny that the movement, though commonly 

 beginning with a fore-limb, may be started by a hind-leg, 

 though in the experience of the writer and those who have 

 observed for him the movement invariably begins in front, and 

 never behind, unless the horse is ' reining back.' The first step 

 taken in walking backwards is always taken with a hind-limb, 

 which appears to support the view that the first step forwards 

 is always made with a fore-limb. On the other hand, the first 

 step in draught may be taken with either a fore or a hind leg ; 

 the former if the draught is easy, the latter when it is heavy. 

 In ' backing ' in draught a hind-foot is first moved if the load 

 be light ; if heavy, the animal leans well back and moves a fore- 

 foot first. If the horse's head be placed uphill he starts with a 

 fore-leg, provided the hill is not steep ; if steep, he starts with a 

 hind-limb. When the head is downhill the first step is taken 

 with a fore-leg. 



A fore-limb having initiated the movement, the next leg to 

 take part is the diagonal hind ; for instance, if the step begins 



