286 
Journal of Agricultural Research 
Vol. XXX, No. 3 
ANALYSIS OF THE MEASUREMENT 
RESULTS 
The measurements were tallied and 
analyzed by ordinary statistical meth¬ 
ods. The means for the length and 
width and wall thickness and the ratio of 
mean length divided by mean width for 
each of the 30 sets of spores are given 
in Tables I to IV. A summary of the 
measurement data is given in Table V. 
The data in Tables I to IV are pre¬ 
sented graphically in Figures 1, 2, and 
3. Each point on the graphs in Figure 
1 represents the mean of the measure¬ 
ments of 100 spores; each point on the 
graphs in Figure 2 represents the mean 
of the measurements of the walls of 50 
spores; and each point on the graphs 
in Figure 3 represents the quotient 
obtained by dividing the mean of the 
length measurements of 100 spores by 
the mean of the width measurements 
of the same spores. The points are 
connected by the solid line for Cronar - 
tium ribicola and the broken line for 
Cronartium occidentale in order to facil¬ 
itate reading. 
Table I.— Field series; means for each 100 urediniospores measured; Cronartium 
ribicola 
Forest 
path¬ 
ology 
No. 
Host 
Locality 
Date collected 
Mean 
length 
Mean 
width 
Mean 
wall 
thick¬ 
ness 
Ratio 
mean length 
Set 
No. 
mean width 
2607 
Ribes vulgare... 
Font Hill, Ont. 
June 6,1915 
23735 
.do. 
North Conway, N. H_ 
July 4,1917 
34070 
--do- 
Red Bank, N. J. 
Aug. 13,1919 
>22.7 
14.6 
1.61 
1.56 
1 
23870 
_do.. 
Rochester, N. Y_ 
Aug. 2,1917 
22216 
_do- 
Chalmers, Ma^s_ 
Aug. 11,1916 
34430 
_do.. _ _ 
Pomroy, Minn . _ 
July 26,1919 
23105 
_do.. 
Little Compton, R. I. 
Aug. 1711916 
23205 
.do_ 
Acton Corner, Me.... 
Aug. 30,1916 
■ 22.6 
14.7 
1.60 
1.54 
2 
23254 
Ribes reclinatum 
Bar Harbor, Me. 
Oct. 2,1916 
22443 
.do.. 
Newport, R. I_ 
Sept. 5,1916 
2592 
.do. 
Lyndonville, Vt_ 
Sept. 12 ,1914 
34260 
_do_ 
Shafer, Minn_ 
Sept. 29 ,1919 
23888 
Ribes nigrum_ 
Rochester, N. Y_ 
Aug. 18,1917 
22.9 
14.8 
1.60 
1.55 
3 
23012 
.do..:._ 
Warwick, R. I_ 
July 21 ,1916 
23846 
-do.. 
North Whately, Mass. 
July 26,1917 
34442 
.do.... 
Cannon City, Minn. _ 
July 30,1919 
23902 
_do.. 
Tupper Lake, N. Y.__ 
Aug. 22,1917 
24021 
.do.. 
Red, Bank, N. J_ 
Aug. 21,1918 
■ 23.8 
15.9 
1.80 
1.50 
4 
20623 
_do_ 
Font Hill, Ont.. 
Aug. 13,1915 
25337 
_do_ 
Temple, N. H_ 
June 10,1919 
23218 
_do.. 
Limerick, Me.. 
Sept. 4,1916 
34036 
_do__ 
Amery, Wis_ 
July 11,1919 
23020 
Ribes hirtellum. 
Lyman, Me.. 
July 25; 1916 
oq 7 
15 2 
1 61 
1 56 
5 
23734 
.do.. 
Bath, N. H_ 
July 2,1917 
34435 
Ribes oxyacan- 
tlioidcs • 
Pomroy, Minn.. 
July 28,1919 
29632 
_do_ 
Rice Lake, Wis.. 
Sept. 18,1918 
24043 
Ribes cynosbati. 
West Greenwich, R. I. 
Oct. 15,1918 
24032 
.do.. 
Bartlett, N. H_ 
June 13,1918 
• 23.8 
14.9 
1.79 
1.60 
6 
20695 
_do.. 
Norfolk, Conn_ 
June 13,1916 
2606 
.do__ 
Font Hill, Ont_ 
June 26; 1915 
23868 
_do.. 
Stephentown, N. Y_._ 
Aug. 4,1917 
34446 
_do_ 
Sec. 26, R. 21 , Minn... 
Aug. 1,1919 
34103 
.do. 
Clear Lake, Wis_ 
July 23,1919 
23.7 
14.8 
1.61 
1 . 60 
7 
25334 
.do.. 
Bethel, Vt_.. 
July 6,1919 
4 
22137 
Ribes ameri- 
Central Village, Mass. 
July 6,1916 
canum. 
24045 
.do. 
Font Hill, Ont. 
June 22,1917 
23764 
.do__ 
St. Johnsbury, Vt_ 
July 20; 1917 
34235 
-do. 
Munch Township, 
Sept. 21,1919 
Minn. 
23.6 
14.9 
1.70 
1.58 
8 
34537 
.do.. 
Downing, Wis. 
Aug. 26,1919 
22165 
Ribes glandulo- 
Norfolk, Conn. 
July 3,1916 
sum. 
23859 
.do__ 
Bartlett, N. H.. 
July 28,1917 
28232 
_do_ 
Brunswick, Me_ 
May 22,1918 
23877 
.do... 
North Thetford, Vt... 
Aug’. L1917 
23.9 
14 6 
1 82 
1 64 
9 
24321 
_do_ 
Amery, Wis_ 
Aug. 11,1916 
24019 
Ribes triste. 
Tuckerman Ravine, 
Aug. 3; 1918 
N. H. 
23365 
.do. 
Rush Lake, Minn- 
June 14,1918 
34095 
Ribes odoratum. 
Petersham, Mass. 
July 30,1919 
23125 
.do. 
TCittery, Me_ 
Aug. 18,1916 
. 24.0 
15.0 
1.68 
1.56 
10 
23834 
.do. 
Keeseville, N. Y_ 
July 24; 1917 
23798 
_do_ 
Orford, N. H. 
July 11,1917 
