UNDER THE APPLE-TREES 



such a vast period of time, that their survival value 

 from generation to generation is and must be very 

 slight. 



Take the case of the horse, for instance. The 

 development of the horse seems to stretch over a 

 period of at least three millions of years, or from the 

 eohippus of Eocene times, an animal less than two 

 feet high, and probably weighing less than one 

 hundred pounds, to the horse of later Tertiary 

 times, the pliohippus, much like the superb crea- 

 ture we know to-day, five feet high, and weighing 

 ten or twelve hundred pounds. If this animal in- 

 creased in height only one quarter of an inch in 

 ten thousand years, he would be six feet high in 

 less than two million years. So if we allow him three 

 million years to develop in, his increase in height 

 must have been even less than one fourth of an 

 inch in ten thousand years. Think of it ! Our horse 

 of to-day might be increasing or diminishing in 

 size at that rate and the fact never be noticed dur- 

 ing the whole historic period. In weight the same; 

 one eighth of a pound in one hundred years, and 

 he would weigh fourteen thousand pounds in less 

 than two million years, a rate of increase that our 

 scales would hardly detect in a century of time. 

 The transformations of the other animals have 

 probably been equally slow. Science would feel 

 safe in saying that a flying fish never becomes a 

 bird, but can we conceive how slight the change 

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