Experiments and their Verification 141 



the result of the same conditions of ground surface, that is, a smooth 

 straight piece of ground slightly downhill, therefore, indicate a marked 

 improvement in action and extension. We see, again, that such total 

 variations have another meaning, namely, that of greater or lesser ac- 

 tivity of each leg. For instance, it was found that the greater variations 

 in fore legs belong to the leg that precedes its mate, and the greater va- 

 riations of hind legs belong to the leg that lags or follows its mate 

 (see Figs. 97 and 94). We shall recur to this peculiar indication of ac- 

 tivity later on. Incidentally it may be remarked right here that as a 

 rule greater weight in shoe has a tendency to fold the fore leg more 

 and hence shorten its extension and that with hind feet the opposite is 

 true, namely, the increase of weight will increase extension and pre- 

 vent high action of the foot so shod. This applies more particu- 

 larly to one fore or one hind with .reference to their respective op- 

 posite mates. Of course, it is also to be understood that the shape of 

 shoes and other conditions are alike. This different influence of weight 

 on fore and hind has its cause in the folding of the knee and hock 

 joints and in the general attachment of legs to the body. The fore 

 are more or less rigidly fixed while the hind, though lacking in folding, 

 are more loosely hung from body. A study of the trajectories or 

 curves of motion in the earlier part of this book will indicate the effect 

 of weight on fore and hind ; and further proof of this matter will be 

 offered later on. 



The effect of such a heavier left hind shoe on the animal in ques- 

 tion was, therefore, very beneficial to the gait, even though it did not 

 quite eliminate her habit of reaching forward with right hind. In 

 fact, because she did so was evidence that the turn required such a 

 way of locomotion. It should not be forgotten, however, that the 

 minute such uneven extension becomes excessive the benefit is lost and 

 danger from interference arises. 



III. TOE-WEIGHTS. 



Before investigating this and other cases any further it will be 

 necessary to say a few words about Toe-W eights. 



