228 THE SURVIVAL OF THE UNLIKE. [x. 



duces large numbers of green and yellow fruits. Even 

 within our own limits there are great variations in this 

 respect which proceed entirely independently of mere 

 flavor, — a subject further discussed in Essay XVI. 



In many varieties the seed -production has decreased, 

 and it has been held by some that there is a correla- 

 tion between this decrease and quality. The chief ex- 

 ponent of this hypothesis is Dr. E. Lewis Sturtevant, 

 who has made a full discussion of the subject in a re- 

 cent paper,* in which he asserts that "there seems to 

 exist in fruits a correlation between seedlessness and 

 quality, especially when that quality is expressed by the 

 term tenderness of tissue. In fruits of fine quality, ten- 

 derness of the seed coating often seems a marked char- 

 acteristic, as in grapes, where the seeds of the improved 

 varieties are distinctly softer and more brittle than in 

 those of the wild species ; as in peaches and plums, 

 where the tendency of a split stone is often notice- 

 able in fruit of varieties of high quality." I have 

 made no studies concerning the strength or thickness 

 of seed -walls in cultivated fruits, but I do not doubt 

 that there is a general tendency towards fragility. 

 But I cannot look upon this tendency, if it exists, 

 as in any way related to quality. It is undoubtedly 

 due to constant selection for small -seeded fruits. 

 Concerning the relations of seed - production to ame- 

 lioration, I made some careful studies a few years ago ;t 

 and as subsequent study and observation have only 

 confirmed the conclusions at which I then arrived, I 

 may be pardoned for borrowing my present argument 

 from that paper. The paper in question dealt with 



*Mem. Torr. Bot. (Mub. i. No. 4 (1800). 



tProc. Amer. Pom. Soc., 1887, 120. Reprinted on p. 251. 



