July 14 , 1923 
Degeneration Diseases of Irish Potatoes 
57 
effect here, the third and fourth lots both having had mosaic throughout 
for several years. 
With spread in the field and perpetuation in the tubers demonstrated, 
infection experiments are of interest. As described in connection with 
mild mosaic(p. 50 and Table II) and with leaf-rolling mosaic (p. 51), aphids 
transmitted the spindling-tuber disease in insect cages in 1921 to three 
hills. The controls, in the same tuber units but in different cages, 
were healthy in both generations. 
Table IV .—Correlation of width with length and depth in Green Mountains grown 
in 1921 
Length (centimeters). 
Depth (centimeters). 
Lot No. 
CT-28 
CT -29 
V-6Bs. Spindling 
tuber. 
V-6B. Healthy. 
CT-13. Caribou 
loam. 
CT-13. Washburn 
loam.. 
MSS-S4 
Width. 
4 
5 
6 
7 
8 
9 
10 
4 
5 
6 
7 
8 
9 
10 
4 
5 
6 
7 
8 
9 
10 
4 
5 
6 
7 
8 
9 
10 
4 
5 
6 
7 
8 
9 
10 
4 
5 
6 
7 
8 
9 
10 
4 
5 
6 
7 
8 
9 
10 
6 
7 
8 
9 
10 
11 i 
1 
12 
13 
14 
is 
16 
4 
5 
6 
7 
8 
a 1 
I 
2 
I 
8 
I 
I 
7 
21 
I 
7 
IO 
1 < 
8 
XO 
1 
33 
19 
.... 
3 
x 
4 
4 
3 
1 
X 
14 
1 
X 
1 
2 
3 
I 
I 
5 
I 
O 
I 
6 
II 
10 
3 
5 
8 
29 
1 
7 
8 
II 
7 
5 
2 
32 
9 
/ 
6 
1 
4 
5 
.... 
1 
.... 
3 
11 
3 
.... 
2 
2 
* ' ’ * 
7 
IQ 
21 
Q 
14 
45 
* * 
4 
x 
12 
l6 
y 
19 
17 
3 
2 
x 
57 
X2 
. . . • 
2 
5 
2 
3 
2 
X 
X 
4 
IO 
I 
I 
X 
1 
I 
1 
I 
12 
2 
2 
19 
X 
2 
6 
I X 
6 
7 
A 
I 
24 
15 
2 
c 
10 
6 
4 
5 
5 
21 
2 
0 
I 
6 
3 
3 
1 
1 
8 
s 
I 
6 
7 
A 
I 
5 
14 
2 
2 
0 
4 
I 
2 
3 
I 
19 
3 
9 
A 
ID 
y 
1 
6 
2 
2 
- 
15 
15 
X 
O 
I 
4 
2 
I 
4 
2 
7 
A 
4 
12 
5 
.... 
O 
I 
2 
2 
4 
O 
X 
X 
3 
2 
I 
I 
c 
A 
2 
2 
x 
3 
11 
2 
J 
2 
4 
6 
6 
8 
A 
2 
I 
25 
7 
• • • • 
2 
O 
2 
IO 
0 
c 
4 
16 
15 
1 
. . . • 
O 
I 
2 
y 
5 
0 
2 
O 
5 
2 
9 
4 
I 
2 
2 
4 
X 
I 
1 
2 
x 
2 
2 
3 
.... 
2 
6 
Q 
6 
2 
12 
13 
y 
0 
8 
8 
8 
2 
I 
7 
28 
5 
4 
2 
3 
2 
1 
I 
r 
X 
3 
6 
1 
0 Figures show numbers of tubers with dimensions indicated at left and at top. 
