76 The Potato 



No correlation has been discovered between color of 

 tubers and color in the stems and flowers. 



In certain varieties there seems to be a coupling of 

 characters and what appears to be a close correlation. 

 This same association, however, may not hold for any 

 other variety. As East points out, we ought to have a 

 good understanding of the life history of different varie- 

 ties before we draw definite conclusions as to the correla- 

 tion of characters. 



Appearance of bud sports 



Occasionally, a single bud, or group of buds, on a tuber 

 will give rise to a plant distinctly unlike any others of 

 the variety. This is known as bud-sporting. Just 

 what causes this unusual behavior we can only speculate 

 upon. No definite cause is known. 



Darwin reports three cases of bud sporting. A tuber of 

 the purple variety "Forty-fold" had a single eye that was 

 white. This when planted gave rise to a white variety. 

 The same purple variety in another instance produced a 

 white tuber which bred true. The white variety " Kemp " 

 sported to give the red "Taylor's Forty-fold." 



Fruwirth reports a case where a yellow tuber gave 

 rise to a violet-skinned form. Examples of this sort 

 are rather numerous. 



Such bud sporting is not limited to characters of the 

 tuber. Many believe that habit of vine, vigor, produc- 

 tiveness and other characters may be affected by sporting 

 of the tuber buds. 



By carefully examining the hills of the breeding plot 

 at digging time, any valuable bud sports can be selected 

 out for further propagation. 



