116 BUD-MUTATION IN THE POTATO AND ITS AGRICULTURAL SIGNIFICANCE 
The 11 tubers from the ordinary stems gave 2 males” and 9 normal 
plants. 
The 6 other tubers gave 6 normal plants. 
The , males” are considerably taller, flower longer and more pro- 
fusely, die off later and produce tubers of a bad shape. The stolons are 
longer, the males” are not no susceptible to Phytophthora infestans. 
Furthermore it could be shown experimentally, that the „Red Star” 
(red stem and nerves, even red tubers; PI. 1, fig. I) have produced the 
following bud-mutants: | 
1. Variegated Red Star: These have red-speckled tubers, the red 
colour occuring especially under the eyes, the foliage is somewhat 
lighter than that of the ordinary „Red Star” (Pl. 1, fig. E and F). 
2. Green Red Star: These are almost free from anthocyanin in the 
stem and nerves. The tubers are red with yellow speckles, especially 
under the eyes. (PI. 1, fig. G and H). These „green Red Stars” remain 
small and give a small yield (‚Green Red Stars” are also found which 
are not inferior in development to the ordinary „Red Star’’). 
Anatomical investigation showed that the anthocyanin of the tuber 
is found in some of the cells of the corkcambium and in the parenchyma 
situated below this cambium (see fig. 18, p. 72). The number of coloured 
cells and the intensity of the colour increases as the colour of the tuber 
becomes more intense. Injured tubers exposed to light at a temperature 
of 13°—16° C. produced much anthocyanin, especially in the vascular 
tissue and in the corkcambium (fig. 19, p. 73). No difference was observ- 
able between the ordinary ,Eigenheimer”’ and the „blue Eigenhei- 
mer”. The difference in colour of the , blue Eigenheimer’’ (blue-violet) 
and the „Red Star” (red-violet) is not (or not only) a consequence of 
difference in reaction. On heating the skin of the blue Eigenheimer and 
of the Red Star with a weak solution of hydrochloric acid different co- 
loured filtrates were obtained. A layer of fluid of 10 mM. depth, gave 
the following results (OBERTHUR 42): 
Filtrate of „blue Eigenheimer” No. 152 tinge 1, rose lilac. 
Filtrate of „Red Star” No. 126 tinge 2, rose salmon. 
The observed budmutations cause, particularly, alterations in color 
and in the development of the foliage. Such alterations are the ones 
most easily: discerned. On the other hand, bud-mutants causing a 
change in yield, taste or percentage of starch etc. are, in the midst of 
