Germination of Helianthus annuus. 701 
it. The air before its entrance into the apparatus first passed through 
a soda-lime tube, then through a wash-bottle containing 30 % sodium 
hydroxide, then through baryta water, and finally through concentrated 
sulphuric acid. That the baryta water showed no signs of turbidity was 
a sufficient indication that the air entering the apparatus was entirely free 
from carbon dioxide. To avoid the increased pressure due to condensation 
of the moisture in the bends of the glass tubes connecting the jars, the 
apparatus was taken apart once or twice during the growth of the advanced 
stages and the tubes dried. This was always done at night and the 
apparatus again set to work, so that by daylight the air in the apparatus 
was free from carbon dioxide. This method of growing the seedlings has 
the advantage not only of preventing photosynthesis and absorption, but at 
the same time it supplies the plant with oxygen and provides it with the 
normal light conditions. The carbon dioxide liberated by the seedling by 
respiration during the daylight is, under these conditions, probably used in 
photosynthetic processes before it leaves the plant. There seems to be no 
possible means of preventing the C 0 2 thus liberated from being utilized by 
the plant in daylight. 
In many of the experiments carried out on seedlings the analyses have 
been made upon material obtained by grinding up the whole seedling. 
Without making separate analyses of the hypocotyls and cotyledons in 
a seedling of the type of the sunflower, it would be impossible to obtain 
a correct insight into the metabolic changes taking place in the reserve 
material and the manner of their transportation from place to place. In 
this work separate analyses were made of the hypocotyls and cotyledons. 
The seedlings were taken at the different stages, and after carefully washing 
them to free the sand, the hypocotyls were separated from the cotyledons 
by means of a razor. The two parts were then ground up separately and 
dried according to the process described below. In preparing the seeds for 
analysis the hulls were removed and the tip or rudimentary hypocotyl and 
root were removed from the cotyledons. The tips and cotyledons were 
dried down separately in the same manner as below mentioned. 
STAGES EXAMINED. 
Seeds. The seeds of Helianthus annuus contain as a reserve material 
between 50 and 56 % of ether extract and about 25 % of proteid matter. The 
oil, according to Thorp, 1 consists of the glycerides of oleic, palmitic, ara- 
chidic, and linoleic acids. The amount of free acid present in the ether 
extract in the seeds used in this work amounted to less than one per cent. 
There is also a non-reducing sugar present to the amount of nearly 4 %. 
This has been identified by Frankfurt^ as saccharose. No starch is present, 
and only a trace of reducing sugar. 
1 Thorp, Outlines of Industrial Chemistry, p. 326. 
5 l.c. 
