288 
Journal oj Agricultural Research 
Vol. XXX, No. 3 
Table III .—Block Island series; means for each 100 urediniospores measured; 
Cronartium ribicola and Cronartium occidentale 
CRONARTIUM RIBICOLA 
Forest 
path- 
Host 
Locality 
Date collected 
Mean 
length 
Mean 
width 
Mean 
wall 
thick¬ 
ness 
Ratio 
mean length 
Set 
No. 
ology 
No. 
mean width 
34555 
34556 
34579 
Ribes odoratum. 
_do__. 
_do.. 
Block Island, R. I. 
_do.-- 
.do--- 
June 22,1920 
June 22,1920 
July 20,1920 
Sept. 8,1920 
Sept. 30,1920 
24.0 
23.5 
23.6 
15.0 
14.6 
15.5 
1.80 
1.87 
1.57 
1.61 
1.61 
1.53 
1.49 
1.60 
11 
12 
13 
14 
15 
34622 
34878 
34881 
34558 
34619 
34888 
34880 
.do. 
do__ __ _ _ 
_do-- 
.do.... 
22.4 
24.0 
15.1 
15.0 
1.83 
1.74 
Sept. 30,1920 
23.8 
15.8 
1.73 
1.51 
16 
17 
Ribes nigrum 
(Naples). 
_do_.. 
June 22,1920 
23.2 
15.2 
1.56 
1.53 
Sept. 8,1920 
Sept. 30,1920 
21.3 
14.7 
1.75 
1.45 
18 
19 
Ribes ameri- 
canum. 
Ribes pros¬ 
tratum. 
do_ 
21.6 
14.6 
1.73 
1.48 
do _ 
Sept. 30,1920 
23.4 
15.6 
1 .73 
1. 51 
20 
CRONARTIUM OCCIDENTALE 
34568 
34574 
34630 
34634 
34846 
34877 
34627 
34871 
34647 
34633 
Ribes odoratum. 
.do_ 
_do.. 
.do__.— 
_do_ 
_do__. 
Ribes nigrum 
(Naples). 
_do.— 
Ribes ameri- 
canum. 
Ribes pros¬ 
tratum. 
Block Island, 
_do.- 
.do. 
_do.. 
_do—. 
_do. 
.do. 
.do. 
_do. 
_do. 
R. I. 
June 23,1920 
June 30,1920 
Sept. 9,1920 
Sept. 9,1920 
Sept. 9,1920 
Oct. 1,1920 
Sept. 9,1920 
Oct. 1,1920 
Sept. 9,1920 
Sept. 9,1920 
25.7 
14.6 
2.39 
1. 77 
24.9 
15.2 
2.52 
1.64 
26.9 
14.5 
2 . 26 
1. 85 
24.4 
13.8 
1.96 
1.77 
24.2 
15.7 
2.03 
1.54 
24.4 
14.6 
2.34 
1.67 
23.5 
14.7 
1.99 
1.60 
24.7 
15.4 
2 . 20 
1.61 
25.0 
15.5 
2.07 
1.60 
24.5 
15.0 
2.08 
1.63 
11 
12 
13 
14 
16 
16 
17 
18 
19 
20 
Table IV. — Washington, D. C., greenhouse series; means for each 100 uredinio¬ 
spores measured; Cronartium ribicola and Cronartium occidentale 
CRONARTIUM RIBICOLA 
Forest 
path¬ 
ology 
No. 
34684 
34697 
34722 
34826 
36466 
34712 
34740 
36125 
36465 
36470 
Host 
Locality 
Date collected 
Mean 
length 1 
Ribes aureum... 
_do. 
_do... 
_do.. 
do 
Washington, D. C- 
.do.. 
_do__- 
.do.... 
_do__ 
July 15,1920 
Aug. 2,1920 
Aug. 25,1920 
Oct. 8,1920 
July 21, 1920 
Aug. 11,1920 
Aug. 4,1920 
July 8,1920 
Aug. 9,1920 
Aug. 9,1920 
22.0 
25.5 
24.3 
25.6 
23.8 
24.6 
22.3 
23.3 
25.4 
23.7 
do 
_do_ 
_do_ 
_do. 
.do. 
dn 
_do. 
_do... 
_do... 
_do—.. 
Mean 
width 
Mean 
wall 
thick¬ 
ness 
Ratio 
mean length 
mean width 
15.0 
1.84 
1.47 
15.2 
2.24 
1.67 
16.1 
1.99 
1.51 
17.7 
2.29 
1.44 
14.9 
1.84 
1.68 
15.1 
2.11 
1.63 
15.5 
2.06 
1.44 
14.5 
1.95 
1.61 
16.1 
1.87 
1.57 
14.3 
2.01 
1.66 
Set 
No. 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
CRONARTIUM OCCIDENTALE 
36104 
36150 
36233 
36406 
36439 
36446 
36078 
36131 
36404 
36429 
Ribes aureum... 
.do. 
.do__ 
_do_ 
Washington, 
_do_ 
_do.. 
_do_ 
_do. 
_do__ 
_do. 
.do.. 
.do.. 
_do__ 
_do. 
.do. 
do— . _ 
_do_ 
July 1,1920 
July 2,1920 
Aug. 17,1920 
May 22,1920 
Aug. 2,1920 
Aug. 9,1920 
July 8,1920 
July 14,1920 
June 22,1920 
June 9,1920 
24.0 
16.1 
2.19 
26.0 
15.8 
2.29 
25.9 
16.7 
2.66 
25.0 
15.5 
2.22 
24.0 
15.4 
1.99 
25.3 
15.3 
2.05 
24.9 
14.3 
2.07 
25.2 
16.7 
2.11 
25.5 
16.1 
2.11 
24.2 
15.3 
1.93 
1.49 
21 
1.65 
22 
1.55 
23 
1.62 
24 
1.57 
25 
1.65 
26 
1.75 
27 
1.51 
28 
1.58 
20 
1.58 
30 
