Germination of II eli ant hits annnus . II. 897 
the percentage of fatty acids insoluble in water that is yielded on the sapo- 
nification of the oil. The determination, then, of the insoluble fatty acids of 
an oil gives some information as to its composition. Thus, if the oil con- 
tained in the seed shows during the course of germination a decrease in the 
percentage of insoluble fatty acids, it indicates that the higher fatty acids are 
being replaced by those of the lower groups which are soluble in water. 
The percentages of total insoluble fatty acids present in the ether extract 
and in the neutral oil of the seed are, respectively, 95-4 and 94*6. The values 
thus are practically identical. These values remain constant for both the 
neutral oil and ether extract until Stage IV of the seedling, when seven- 
eighths of the original oil of the seed have disappeared. At this period there 
is a considerable decrease in the amount of insoluble fatty acids in both the 
neutral oil and the ether extract. The decrease, however, is almost identical 
in both, so that the amount of insoluble fatty acids remaining in each is 
practically the same. The amount in the ether extract is 87-6 per cent, and 
in the neutral oil 88*9 per cent. In the last stage of germination the 
amount of insoluble fatty acids in the ether extract falls to 84*8 per cent. 
The percentage of insoluble fatty acids in the ether extract of the 
hypocotyls and roots in Stage I when they had reached a length of 3-5 
to 5 cm. was 89-6, a value considerably lower than that of the original seed. 
This value remains the same during the two stages of the seedling, and then 
rapidly decreases until the value has fallen to 57-2 in the last stage of the 
seedling examined. 
The determination of the insoluble fatty acids indicates that there is 
no change in the solubility of either the combined or free fatty acids of the 
oil of the cotyledons until a late stage of development, when nearly all the 
oil has disappeared. At least, up to that time there is, as will be explained 
later, no accumulation of soluble acids that can be detected. In the hypo- 
cotyls and roots, however, the decrease in the amount of insoluble fatty 
acids of the ether extract at the first stage of the seedling indicates that in 
these organs from the beginning of germination the insoluble fatty acids 
are being replaced to a small extent by the fatty acids which are soluble 
in water. This replacement becomes very marked in the last two stages 
of the seedling. 
Total Soluble Acids. The total soluble acids of an oil represent both 
the free and combined acids of the oil which are soluble in water, and 
represent the fatty acids of lower molecular weight. The amount of acids 
soluble in water in the ether extract and the neutral oil of the seed is less 
than 1 per cent. This value remains almost constant for both until the 
last stage of the seedling examined, when it suddenly rises to 4*5 per cent, 
of the ether extract and 3 per cent, of the neutral oil. It seems evident 
from the results that no fatty acids of the lower series are produced from 
the oil in the cotyledons until only a small part of the original oil remains. 
3 N 
