896 
Miller . — A Physiological Study of the 
the amount of free add in the ether extract estimated as butyric gives 
a value two to three times greater than that found in the estimation of the 
total soluble acids. In the last two stages, however, the amount of free acid 
estimated as butyric would be less than that of the total soluble acids shown 
to be present. This fact is probably due to the presence of glycerides of 
lower molecular weight in the ether extract at those stages. 
From the above it seems evident that in the ether extract of both the 
cotyledons and hypocotyls of the sunflower free fatty acids of high molecular 
weight are present. This can be determined definitely, however, only by 
a qualitative study of the acids present. 
Saponification Value . The saponification equivalent or value of an oil 
is the amount of caustic potash in milligrams that is neutralized during the 
saponification of one gramme of the oil by the combined and free fatty acids 
which it contains. It is in reality an indication of the mean molecular 
weight of the fatty acids which enter into the composition of the oil. Thus 
oils which are glycerides of the higher fatty acids give a lower saponification 
value, while those that are glycerides of the lower fatty acids give a higher 
saponification value. 
The saponification value of the ether extract and neutral oil in the 
cotyledons of the seed is the same. There is no change in the saponification 
number of either the ether extract or the neutral oil until the last stage of 
the seedling examined, when only 5-3 per cent, of the original ether extract 
remains in the cotyledons. The marked increase of the saponification value 
of both the neutral oil and ether extract at the last stage of the seedling is 
significant in the fact that it is the first indication given of the presence of 
glycerides or free fatty acids of lower molecular value than those originally 
contained in the cotyledons of the seed. 
In the hypocotyls and roots the saponification value of the ether 
extract begins to increase only in the later stages of development of the 
seedling. It is a very striking fact that the saponification value of the ether 
extract in the hypocotyls and roots is identical with that of the oil contained 
in the cotyledons of the seed and seedling up to a period when the hypocotyls 
and roots have attained a length of 7-5 to 11 cm. and one-half of the oil 
originally present in the seed has disappeared. Even after the cotyledons 
are above ground and spread out perpendicular to the hypocotyl, and after 
over two-thirds of the original oil has disappeared from the seedling, the 
saponification value of the ether extract of the hypocotyls and roots has 
increased but slightly over that of the oil of the cotyledons. Up to the 
time when two-thirds of the original oil has disappeared from the cotyledons 
we can say, then, that the saponification values of the oil in the cotyledons 
and hypocotyls and roots are practically identical with the saponification 
value of the original oil of the seed. 
Total Insoluble Acids. By the total insoluble acids of an oil is meant 
