l6o DOMESTICATED ANIMALS AND PLANTS 



that mediocrity is the most common and the most Hkely lot of 

 man, and that regression is always at work. 



Progression. Now let us look at the other side of the ques- 

 tion and see what is to be found after having disposed of this 

 relatively large number of mediocre individuals, and let us see 

 if, after all, the exceptional parent has not something to his 

 advantage in the matter of offspring. 



Note again that the other end of this array of the offspring 

 of the 70.5-inch parents shows 17 individuals, or exactly one 

 fourth, better thaii their exceptioiially good parents. Not onl) 

 is this true, but the higher we get among the exceptional parents, 

 — 71.5, 72.5, etc., — the more is this true and the larger is the 

 proportion of exceptional offspring. This is progression, and, as 

 a principle, it is just as true and just as much to be counted on 

 as are regression and mediocrity. 



This principle of progression is the one that insures the 

 results from natural selection and the survival of the fittest in 

 nature, just as it is the one that insures that selection anywhere 

 will be follozved by offsprings some portion of which, not all, will 

 be a distinct improvement over even their exceptional parents. 

 It is on this principle that we rely for most of our improvement 

 of domesticated animals and plants, and as it is the most impor- 

 tant principle in evolution, the student is urged to remember it. 



The promptness and rapidity with which improvement follows 

 selection under this principle of progression is best shown by 

 the opposite table exhibiting the results of Dr. Hopkins's ex- 

 periments in altering the oil content of the grain of corn. 



In this experiment ears of the highest and others of the 

 lowest oil content obtainable were planted in successive years. 

 The table shows the results in the crop both as to distribution 

 and average for each of nine years, and is the best exhibition 

 known to the author of the principle of progression and the 

 results of selection. 



In the study of this table it will be noticed that the oil content 

 of the original seed was 4.70 per cent, but that the strain 



