228 SELECTION. Chap. XXI. 



horticulturists : if a gardener observes one or two additional 

 petals in a flower, ho feels confident that in a few generations 

 he will he able to raise a double flower, crowded with petals. 

 Some of the seedlings from the weeping Moccas oak were so 

 prostrate that they only crawled along the ground. A seedling 

 from the fastigate or upright Irish yew is described as differ- 

 ing greatly from the parent-form "by the exaggeration of 

 the fastigate habit of its branches." 61 Mr. Shirreff, who has 

 been highly successful in raising new kinds of wheat, remarks, 

 " A good variety may safely be regarded as the forerunner of 

 a better one." 62 A great rose-grower, Mr. Rivers, has made 

 the same remark with respect to roses. Sageret, 63 who had 

 large experience, in speaking of the future progress of fruit- 

 trees, observes that the most important principle is " that the 

 more plants have departed from their original type, the more 

 they tend to depart from it." There is apparently much 

 truth in this remark ; for we can in no other way understand 

 the surprising amount of difference between varieties in the 

 parts or qualities which are valued, whilst other parts retain 

 nearly their original character. 



The foregoing discussion naturally leads to the question, 

 what is the limit to the possible amount of variation in any 

 part or quality, and, consequently, is there any limit to what 

 selection can effect ? Will a race-horse ever be reared fleeter 

 than Eclipse ? Can our prize-cattle and sheep be still further 

 improved? Will a gooseberry ever weigh more than that 

 produced by "London" in 1852? Will the beet-root in 

 France yield a greater percentage of sugar ? Will future 

 varieties of wheat and other grain produce heavier crops than 

 our present varieties ? These questions cannot be positively 

 answered ; but it is certain that we ought to be cautious in 

 answering them by a negative. In some lines of variation 

 the limit has probably been reached. Youatt believes that 

 the reduction of bone in some of our sheep has already been 

 carried so far that it entails great delicacy of constitution. 64 



61 Verlot, 'Des Varietes,' 18(35, p. " 3 ' Pomologie Physiolog.,' 1830, p. 

 94. 106. 



62 Mr. Patrick Shirreff, in ' Gard. 64 Youatt on Sheep, p. 521. 

 Chronicle,' 1858, p. 771. 



