548 Th e Philippine Journal of Science 1920 
having high partial concentrations of magnesium sulphate, es- 
pecially cultures T1R1C1 and T2R1C1. Growth, however, did 
not cease in these injured cultures, for the plants continued 
to enlarge slowly throughout the period. The solutions con- 
taining less magnesium sulphate produced much better growth 
and gave the most healthy appearing plants when the series was 
discontinued. During the latter part of the period these better 
cultures were seen to have much longer lateral roots and their 
tops were lighter green in color and noticeably larger than in 
the injured cultures. 
Rather pronounced differences in the color of the plants in 
different cultures were apparent at the time of harvesting. The 
color ranged from a very deep shade of green to a light yellow- 
ish green. The plants in the cultures along the left-hand mar- 
gins of triangle 1 and triangle 2 (fig. 1) were darkest green, 
while those along the right-hand margins of triangles 4, 5, and 
6, and the culture of triangle 7 were the most chlorotic. In 
general, the depth of green decreased in passing from left 
to right in the triangles and in passing in the tetrahedron from 
triangle 1 to triangle 7. The largest tops were intermediate in 
color. Another morphological difference that appeared was a 
drying and bleaching of the tissue between the main veins, in 
some cultures resulting in longitudinal stripping of the leaves. 
This condition was limited to the cultures in solutions with low 
monopotassium phosphate content, especially rows 1, 2, and 3 
of triangles 1 and 2. 
A very similar symptom was observed by Tottingham in sev- 
eral of his four-salt solutions having an osmotic concentration 
of 8.15 atmospheres. This symptom was found in cultures 
having a high content of monopotassium phosphate, a maximum 
content of potassium nitrate, and approximately equal contents 
of calcium nitrate and magnesium sulphate. A thickening of 
the base of the stem with branching from the same region 
(perhaps equivalent to the “stooling” of wheat in the field) 
appeared in those cultures where root injury was most pro- 
nounced. Such branching of the wheat plant occurs normally 
in the field when the plants are considerably older than these 
plants were. It is suggested that those solutions which were 
unfavorable to root development also brought about symptoms 
of an earlier maturation of the plant. 
The most pronounced morphological modification of the leaves 
appeared to be similar to that described by Tottingham as mag- 
nesium injury; this modification was also observed by Shive. 
