fiO ORGANIC EVOLUTION 



the three bones of the human middle finger; and 

 the horse's fore-hoof is the nail of that finger; 

 whilst the hoof of each of its hind-legs is similarly 

 the nail of the third or middle toe. In point of 

 fact, the horse walks upon the extremities of the 

 nails of its middle (and, as we shall see, only 

 remaining) fingers and toes. Place your tAvo 

 middle fingers upright on this page, with only 

 the nails touching the paper, imagine the thumbs 

 and remaining fingers, together with the bones that 

 support them, to be absent; bend the wrists for- 

 ward, as the horse's so-called knees are bent, and 

 you will obtain some idea of the highly specialised 

 manner in which the horse walks. Lastly, let us 

 note that the horse's cannon-bone is supported on 

 each side by two small and useless bones, to which 

 no fingers are attached, but which must be regarded 

 as corresponding to the second and fourth meta- 

 carpal bones of the human or any other vertebrate 

 hand. Occasionally there is born a foal whose 

 hands and feet contain further rudimentary bones 

 which obviously approximate them still further to 

 the general vertebrate pattern. 



Here I omit any description of the horse's 

 teeth, and will proceed to quote a paragraph from 

 Huxley, 1 which serves fitly to introduce the next 

 part of this chapter : — 



Hence the general principles of the hypothesis of evolu- 

 tion lead to the conclusion that the horse must have been 

 derived from some quadruped which possessed five complete 

 digits on each foot ; which had the bones of the forearm 



1 " Lectures on Evolution." 



