May, 1921] 
DICKSON — COMPOSITION OF OAT PLANT 
269 
The average phosphorus content of all the grain analyzed each year, as 
given in table 9, is: 0.679 percent in 1915, 0.976 percent in 1916, and 1.570 
percent in 191 7. The increases in phosphorus content of the straw are 
equally great. This stands out in extreme contrast with the phosphorus 
content of the grain and straw of the plants grown in the phosphorus- 
deficient solutions, which show no influence of climate on composition. 
The calcium content of the grain produced in all the cultures, including the 
calcium-deficient solutions, is highest in 1917 and lowest in 1915. The 
calcium content of the straw, on the other hand, is not greatly influenced 
by seasonal differences. Certain other differences are brought out in 
comparing the data presented in tables 4 and 7 and summarized in table 9, 
but before they can be discussed intelligently a more complete analytical 
study is necessary together with more detailed meteorological records. 
Table 10. The Mean Daily and the Average Monthly Air Temperatures at Pullman, 
Washington, and Madison, Wisconsin, for the Duration of the Cultural Experiments 
Mean Daily Air Temperature by Months 
May 
June 
July 
August 
Days 
Pullman 
Madi- 
Pullman 
Madi- 
Pullman 
Madi- 
Pullman 
Madi- 
son 
son 
son 
son 
igi6 
1917 
1915 
1916 
1917 
1915 
1916 
1917 
1916 
1917 
I 
38 
52 
42 
56 
51 
53 
70 
57 
69 
74 
64 
72 
2 
45 
54 
42 
44 
52 
48 
72 
53 
61 
80 
63 
68 
3 
51 
55 
46 
57 
52 
60 
74 
51 
59 
70 
63 
68 
4 
55 
38 
63 
57 
61 
72 
55 
64 
69 
61 
72 
5 
58 
40 
65 
46 
54 
62 
60 
68 
76 
62 
73 
6 
58 
51 
44 
62 
52 
59 
66 
62 
66 
70 
67 
68 
7 
60 
38 
48 
64 
56 
54 
63 
69 
70 
71 
67 
68 
8 
60 
42 
48 
55 
60 
61 
60 
73 
75 
70 
60 
62 
9 
55 
37 
46 
53 
52 
64 
62 
67 
69 
75 
62 
62 
10 
48 
37 
50 
49 
49 
68 
60 
61 
66 
77 
66 
64 
II 
53 
40 
48 
48 
51 
67 
66 
68 
65 
76 
67 
70 
12 
51 
44 
50 
54 
57 
71 
65 
74 
65 
71 
70 
64 
13 
52 
43 
50 
59 
61 
61 
57 
63 
67 
72 
69 
65 
14 
51 
46 
57 
61 
65 
50 
53 
64 
68 
76 
71 
68 
15 
49 
51 
68 
62 
69 
52 
58 
71 
70 
77 
64- 
72 
16. .... . 
58 
56 
68 
61 
73 
56 
63 
69 
66 
17 
55 
58 
70 
63 
76 
66 
56 
52 
68 
18 
49 
51 
69 
51 
60 
71 
63 
54 
70 
19 
47 
47 
68 
53 
47 
64 
69 
62 
74 
20 
50 
45 
50 
60 
45 
64 
73 
66 
76 
21 
54 
42 
42 
63 
42 
67 
82 
66 
78 
22 
50 
52 
40 
70 
54 
59 
79 
65 
74 
23 
52 
53 
44 
72 
61 
59 
72 
64 
76 
24 
54 
54 
52 
65 
60 
61 
74 
66 
76 
25 
52 
59 
56 
59 
66 
68 
72 
60 
80 
26 
53 
53 
51 
54 
58 
73 
69 
55 
81 
27 
61 
55 
52 
58 
59 
66 
66 
75 
28 
57 
50 
54 
62 
49 
60 
66 
61 
78 
29 
51 
48 
60 
59 
50 
68 
56 
64 
85 
30 
55 
55 
60 
63 
55 
70 
65 
71 
86 
31 
62 
50 
62 
68 
71 
84 
Average . . . 
53 
49 
52 
59 
56 
62 
66 
63 
72 
74 
65 
69 
