20 
Coi.OHADO ExPEHI^IPI^’T StATION 
with (Icci) eyes. In tlie Greeley district this type has been observed 
most frequently in the Pearl variet}^ The abnormal tubers are 
usually pear-shaped with smooth, glossy skin which is generally 
tinged with pink, especially near the stem end. Experiments at 
the station have shown that the crop grown from these tubers is 
similar in character to that of the seed which was planted. So far 
it has been impossible to determine whether this condition was 
reached by successive stages or whether the transition from the 
normal type was sudden as in the case of mutations. While the 
pear-shaped type of tuber is characteristic of this form of degenera- 
tion it does not follow that all tubers of this type are run out, 
at least in certain varieties. For example, in 1918, tubers of this 
shape were selected from the Rural New Yorker and planted beside 
an equal number of tubers of the best type that could be found in 
the same lot of seed. The crop produced by the pear-shaped tubers 
was equally as good, both in regard to quantity and quality, as 
that produced by the good type of seed tubers. 
Apparently in this case there was only a temporary modification 
of the individual tuber which was undoubtedly in some way effected 
by the nutrition of the plant during tuber formation and should 
not be considered a form of degeneration. These instances show 
that different varieties behave differently with respect to running 
out. 
THE GREENING OF SEED 
The variety used for this experiment was the Pearl. The seed 
was greened by spreading it out in a thin layer in trays and expos- 
ing it to strong light until the surface of the tubers had become 
thoroly greened. This re(iuired about two weeks. The spring green- 
ing was done in April and the fall greening the latter part of No- 
vember. Short, thick sprouts were produced during the process 
of greening in the spring. Many of these were bruised or l)roken 
off in planting which was done with a machine. The yields and the 
increases or decreases resulting from greening are given in Table 9. 
The results show that lower yields Avere produced by the seed 
Avhich was greened in the fall than from that which had not been 
greened. It should be stated in this connection that the fall green- 
ing was very unsatisfactory. Because of the lack of strong light 
the greening at that time of the year was not as tlioro as that 
Avhich Avas done in spilng; furtliermore, there Avas some drying oiit 
