900 
Miller . — A Physiological Sludy of the 
groups of the oily material remains the same until all the reserve has dis- 
appeared from the cotyledons. 
The only marked change in the nature of the oily reserve in the cotyledons 
is the increase in the amount of free acid present. The acid value of the 
oily reserve remains constant until over two-thirds of the ether extract have 
disappeared from the cotyledons, when it rises to 4 -6. 
The most marked change in the ether extract at the last stage of seedling 
examined is the amount of free acid present. The acid value of the ether 
extract at that stage is 66-8. Calculated as oleic acid the amount of free 
acid present would amount to one-third of the oily material found in the 
cotyledons at that stage. Some of the free acids present, however, are of 
low molecular weight and soluble in water ; but the greater part of the 
free acid is composed of fatty acids of high molecular weight which are 
insoluble in water. 
The results obtained in this investigation indicate that, with the exception 
of an increase in the amount of free acid, no change takes place in the oily 
reserve of the cotyledons until nineteen-twentieths of the oil originally present 
has disappeared from them. 
The Oily Material of the Hypocotyls and Roots. The saponification 
value of the ether extract of the hypocotyls is practically the same for the 
first three stages of the seedling examined as that of the ether extract of 
the cotyledons at those stages. After the third stage of the seedling the 
saponification value increases rapidly. 
The amount of insoluble fatty acids remains constant during the first 
three stages, but is about 10 per cent, less than the amount of insoluble acid 
present in the ether extract of cotyledons at the same stages. After that 
the amount of insoluble fatty acids falls rapidly and amounts to only 57*2 
per cent, of the oily material present at the last stage of the seedling. The 
amount of soluble fatty acids during the first three stages increases but 
little, but the amount present is greater than that found in the ether extract 
of the cotyledons during those respective stages. During the last two stages 
of the seedling the amount of soluble fatty acids increases rapidly, and amounts 
to 1 8-5 per cent, of the oily matter at the last stage of the seedling. The 
acid value increases gradually from 18-2 at the first stage of the seedling 
to 97-8 at the last stage examined. During the first three stages there is 
evidence that a considerable portion of the free acid is composed of acids 
of higher molecular weight which are insoluble in water. During the last 
two stages, however, the free acids present seem to be composed entirely 
of those of low molecular weight which are soluble in water. 
The iodine number is constant for the first two stages, but is considerably 
less than that of the ether extract of the cotyledons at that time ; after the 
second stage of the seedling the iodine value falls rapidly and amounts to 
only 48*3 at the last stage examined. 
