222 BOTANICAL GAZETTE [MARCH 
TABLE II 
THE RATIO OF LIME TO MAGNESIA IN PLANTS (MAGNESIA CONSIDERED AS 1) 
TO To From 
Kind of plant beni bao Kind of plant Tifetous | normal 
soil soil soil soil 
Pineapple leaves: Ironwood needles....| 8.20 5.56 
5 months old..... 1.58 04 Olive leaves........ 14.30 | E103 
ths old. . 1.98 1.00 altheria americana 
Pineapple stalk: Paves sob ase 8.21 5.44 
ins O10... £5. 14.00 4.10 tes esas 1:28 1/2 
18 months old..... 88 2.24 Broom corn 
Com StOVER Soe. 1.12 Se LOAVES eo a 1.79 1.54 
Cowpeas oli a 1 Rene een Ee .67 -74 
WINGS 0 3.28 1.86 Tobacco stems...... Oe 57 
as Neg gsare arene 35 16 Pigeon peas: 
Paspalum orbiculare..) 1.53 ¥.32 ee Ee ee 4.69 1.02 
uava: terme 42 86 
ee ee eee 11.53 To FES Ee SPR 1.79 1.07 
mies Suntan 34.50 3.62 Wheat straw... ....| 5-42 .76 
Sugar cane leaves ....| 3.25 2.94 Mango leaves....... 15.40 3-49 
Crotalaria (205.0555 3-95 go 
Peanut: 
Leaves 6552.3: 6.28 3.58 
te Ca 1.63 1.14 
instance the ratio of the absorbed lime to absorbed magnesia was 
increased under the influence of manganese. 
Discussion 
In this investigation it has been shown that different plants, 
when grown on manganiferous soils, are affected differently. Some 
species are stunted in growth and die back from the tips of the 
leaves, which turn yellow or brown, and sometimes fall off, and a 
general unhealthy appearance results. Other species appear to 
be unaffected, and, so far as can be judged, vegetate normally in 
the presence of manganese. Microscopic investigations show that 
in certain instances the protoplasm undergoes changes. Occa- 
sionally it draws away from the cell walls and the nuclei become 
brown. There is a manifest change in the protoplasmic contents 
of the roots. 
The chlorophyll in a number of plants is affected; in pineapples 
it undergoes decomposition. Simultaneous with the destruction of 
chlorophyll, starch formation ceases. 
The activity of the oxidizing enzymes in plants is herein shown 
to bear no relation to the destruction of chlorophyll under the 
