[Vor. 7 
30 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
TABLE XIV 
(Series 4, I—Corn [moist, high temperature]) 
SALT REQUIREMENTS AND H-ION CONCENTRATION IN RELATION TO GROWTH 
Total | Gr. wt. | Total | Greatest Pu 
No. Culture gr. wt. | of roots | dry wt. length 
indices | (gms.) | (gms) | (gms) | (cm) | Initial | After gr. 
1 AcO 19.05 4.42 598 34.72 3.4 4.2 
2 Ac /5 27.32 | 6.80 1.786 40.20 4.6 4.6 
9 Ac /10 18.85 3.87 305 38.58 5.8 6.0 
4 Ac 1/ 14.83 | 4.01 1.136 30.48 3.35 6.3 
5 Ac 3/ 9.45 | 3.28 1.129 29.23 3.15 6.4 
6 AcNa 6.44 | 3.09 973 22.77 3.45 6.6 
7 AcM 24.02 4.80 1.615 38.24 5.4 6.5 
8 BcO 22.31 | 4.93 1.781 38.63 6.6 5.2 
9 Be /5 19.77 2.44 1.452 39.65 7.4 6.4 
10 Be /10 21.12 | 4.97 1.538 39.64 8.6 6.1 
11 Be 1/ 20.93 3.81 1.726 40.85 6.4 5.6 
12 Be 5/ 21.55 4.33 1.724 41.25 3.2 4.4 
13 Be 10/ 9.02 | 2.38 .936 22.71 2.8 re 
14 BcK; /10 25.56 | 4.44 1.770 43.46 7.0 5.2 
15 cCa 19.02 2.70 1.572 43.40 7.3 7.9 
16 CcO 20.02 | 4.70 1.396 27.26 4.2 7.7 
17 Cc /5 16.11 3.28 1.105 26.72 6.4 7.4 
18 Ce /20 15.81 4.81 1.207 22.18 7.6 7.9 
19 Ce 1/ 19.81 4.88 1.341 33.56 3.6 7.6 
20 Ce 5/ 26.72 6.67 1.780 31.02 3.2 7.6 
21 CeNa 18.81 3.94 1.165 30.62 4.2 Td. 
about Py 3.2, although there is not the consistency which might 
be expected between cultures AwO, Cw 1/, Cw 5/, and Bw 5/. 
Where the conditions involved a relatively dry atmosphere 
and a high greenhouse temperature the response of the organism 
to the different culture solutions is of special interest. The 
three cultures with highest green weight yields are all in the B 
block, namely, BwO, BwCa, and Bw /5. 'These are so far 
ahead of the cultures in the A and C blocks, irrespective of 
hydrogen ion concentration within the usual range, as to leave 
no doubt whatever that for continued cultivation in the same 
solution for a period of 18 days the B solution is decidedly the 
most favorable culture medium. In this case too we have as 
definite an indication as has been afforded as to the limitation 
imposed by hydrogen ion concentrations. With an exponent 
