FEET AND HANDS

It is evident that, in what is called the evolution of animal forms, the foot came in suddenly when the backboned creatures began to live on the dry land—­that is, with the frogs.  How it came in is a question which still puzzles the phylogenists, who cannot find a sure pedigree for the frog.  There it is, anyhow, and the remarkable point about it is that the foot of a frog is not a rudimentary thing, but an authentic standard foot, like the yard measure kept in the Tower of London, of which all other feet are copies or adaptations.  This instrument, as part of the original outfit given to the pioneers of the brainy, backboned, and four-limbed races, when they were sent out to multiply and replenish the earth, is surely worth considering well.  It consists essentially of a sole, or palm, made up of small bones and of five separate digits, each with several joints.

[Illustration:  AN AUTHENTIC STANDARD FOOT.]

In the hind foot of a frog the toes are very long and webbed from point to point.  In this it differs a good deal from the toad, and there is significance in the difference.  The “heavy-gaited toad,” satisfied with sour ants, hard beetles, and such other fare as it can easily pick up, and grown nasty in consequence, so that nothing seeks to eat it, has hobbled through life, like a plethoric old gentleman, until the present day, on its original feet.  The more versatile and nimble-witted frog, seeking better diet and greater security of life, went back to the element in which it was bred, and, swimming much, became better fitted for swimming.  The soft elastic skin between the fingers or toes is just the sort of tissue which responds most readily to inward impulses, and we find that the very same change has come about in those birds and beasts which live much in water.  I know that this is not the accepted theory of evolution, but I am waiting till it shall become so.  We all develop in the direction of our tendencies, and shall, I doubt not, be wise enough some day to give animals leave to do the same.

It seems strange that any creature, furnished with such tricky and adaptable instruments to go about the world with, should tire of them and wish to get rid of them, but so it happened at a very early stage.  It must have been a consequence, I think, of growing too fast.  Mark Twain remarked about a dachshund that it seemed to want another pair of legs in the middle to prevent it sagging.  Now, some lizards are so long that they cannot keep from sagging, and their progress becomes a painful wriggle.  But if you must go by wriggling, then what is the use of legs to knock against stems and stones?  So some lizards have discarded two of their legs and some all four.  Zoologically they are not snakes, but snakes are only a further advance in the same direction.  That snakes did not start fair without legs is clear, for the python has to this day two tell-tale leg-bones buried in its flesh.