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PACIFIC SCIENCE, Vol. XVII, October 1963 
stained less deeply than those treated with P 
alone. Staining of nuclei was especially pro- 
nounced in the 1,000 lb P treatment. 
The results obtained in this study differ from 
those reported by McLean and Gilbert (1927) 
for corn and cabbage, and by Wright and 
Donahue (1953) for barley, in that cells from 
stelar regions stained readily in all our prepara- 
tions. Although McLean and Gilbert noted stain- 
ing of nuclei and cytoplasm, this staining was 
restricted to the epidermis and outer cortex, and 
none of the stelar cells were stained. Wright and 
Donahue found that staining occurred from the 
epidermis to the outer wall of the endodermis, 
but that there was very little staining in the 
stelar region. 
DISCUSSION 
The importance of the effect of high soil A1 
on root growth cannot be minimized, but shal- 
low root development in the Halii and Kapaa 
soil series was not interpreted as resulting from 
"A1 toxicity.” High soil A1 can cause conditions 
in the soil which may limit root development, 
however. From previous work, it is known that 
A1 can interfere with phosphate nutrition of 
the plant both by precipitation of phosphorus in 
the soil and possibly by precipitation within 
the plant. In addition, A1 is thought to con- 
tribute to the acidity of the soil. If high alu- 
mina content of these subsoils is important in 
limiting root development of plants in bauxitic 
soils, any decrease in extractable A1 and plant A1 
Fig. 6. Photomicrographs of Leucaena glauca roots sectioned and stained with hematoxylin. A, Root sec- 
tion from the untreated (check) subsoil of the Kapaa soil series. B, Section from Kapaa subsoil treated with 
2.5 tons lime. C, Root from Kapaa subsoil treated with 500 lb P. Note heavily stained area in xylem region. 
D, Cross-section of root from Kapaa subsoil treated with 5 tons lime plus 1,000 lb P. Note staining of nuclei, 
cell walls, and cytoplasm. 
