Brenchley . — The Development of the Grain of Barley, 91 1 
representative curves, while differing in proportion, change their direction at 
corresponding periods in all three cases, indicating some correlation in the 
entry of these constituents into the grain. 
A calculation of the ratio between the nitrogen and phosphoric acid 
(expressed in Table II and Fig. 11) yields very interesting results. The two 
normal plots show very similar ratios, while that of C is distinctly higher, 
3 6 ^ 12 15 18 El 24 27 30 33 36 33 42 45 46 days 
Fig. ii. Ratio between the nitrogen and phosphoric acid in the grain. 
TABLE II. 
Nitrogen 
Ratio. 
Period 
j 
Phosphoric acid 
2.324 2.399 
2-603 
77 
2 
1-900 
2.254 
2-544 
77 
3 
1.724 
1.950 
2-122 
97 
4 
1.674 
2-043 
I.996 
77 
5 
1.512 
1*804 
I.987 
77 
6 
1.666 
1-658 
2-148 
77 
7 
i -777 
1-558 
2-233 
77 
8 
1.625 
1-670 
2.428 
77 
9 
1-734 
i-655 
2-565 
77 
10 
1.668 
i -597 
2.501 
77 
11 
1-853 
1-704 
2.503 
79 
12 
1-846 
1.480 
2-443 
77 
13 
J -754 
1-631 
2.384 
77 
14 
i-675 
1.646 
2-354 
77 
15 
1.670 
1.692 
2.464 
,, 
16 
1.861 
1.512 
2.571 
77 
17 
1 "943 
1 - 7°7 
— 
showing that in the presence of plenty of available nitrogen in the soil, but 
with an insufficiency of phosphoric acid, the plant is able to take in a larger 
N 
proportion of nitrogen than when there is no lack of P 2 0 5 . The 7777 ratio 
4 2^5 
falls during the first four or five periods, but eventually rises. In plot C 
a constant level is maintained after the eighth period. 
The theory has been put forward that the P 2 0 5 acts in some way as 
