OUR DEBT TO THE ARAB 37 



not be understood as implying that its further use 

 would therefore work further improvement. For 

 every distinct breed has its distinct and special 

 purpose. And in all well-established breeds — the 

 test of which always is that they shall reproduce 

 themselves unaltered when bred, like sire to like 

 dam — the time for outcrossing has ceased and 

 they are best improved within their own lines. 

 The most striking instance of this is furnished by 

 the thoroughbred. For, although evolved from 

 the Arabian, he is now, as we have stated, a faster 

 horse; and no one could say that (unless lacking 

 in endurance or some other essential quality, which 

 he surely is not) he could be improved by crossing 

 with anything that is slower. 



If a further improvement of the thoroughbred 

 is possible, it must come — as improvement must 

 come in the case of every one of our well-estab- 

 lished animal types — not by new crossings, but 

 by the judicious breeding that aims to develop 

 »nd accentuate the virtues the breed has now. 



