28 Traces of Unity in the 



of the two rudimentary fingers which support the hooflets 

 behind the foot an arrangement of fingers which, as a 

 snow-shoe, prevents the foot from sinking so deeply 

 into the snow as to make it difficult to withdraw it. 

 Thus again, in the miocene extinct horse (Hipparion) 

 living specimens of which have cropped up now and 

 then, not only in the days of Julius Caesar and Leo X. 

 but in modern times also the 2nd and 3rd fingers, 

 which in the modern horse are represented merely by 

 the ' splint-bones ' attached to the side of the ' canon 

 bone ' are developed so as to support the two ' spurious 

 hoofs' which dangle behind the principal hoof. The 

 case, indeed, is plain enough as exhibited in these 

 different forms of hoofed fore-feet. In the elephant are 

 five fingers, the 1st very rudimentary: in the hippo- 

 potamus the ist finger is absent and the 2nd and 5th 

 are small in comparison with the 3rd and 4th : in the 

 rhinoceros the ist and 5th are both absent, and of the 

 remaining three, all large, the 3rd is the largest ; in the 

 deer, the cloven-foot is made up of the 3rd and 4th 

 fingers while the two hooflets behind the foot have to 

 do with the 2nd and 5th fingers : in the ox the differ- 

 ence in the cloven-foot is in the absence of the hooflets 

 of the deer : and so, by watching the way in which this 

 simplification is steadily brought about, on arriving at 

 the horse, it is evident that the foot is now only the 3rd 

 or middle finger, with rudiments of the 2nd and 4th 

 attached to it high up as ' splint-bones,' the bone 

 which is called the ' canon bone ' being the metacarpal 

 bone, while the three bones of the finger proper, reck- 

 oning from above downwards, are called respectively, 

 ' great pastern ' or ' fetter bone,' ' little pastern ' or 

 ' coronary bone/ and ' coffin bone,' the latter being en- 

 cased in the hoof, which, in fact, is the homologue of the 



