Germination of Helianthus annuus . 715 
due to the low water-capacity of the sand, so that the large amount of water 
necessary at the beginning of germination for a maximum advance could not 
be furnished. This may explain why other investigators obtain certain 
stages of the seedlings in a shorter time than the same stages were obtained 
in this work. 
Ash .—The per cent, of ash in the cotyledons remains at about 3-3 
until they are pushing through the ground, after which it gradually increases 
Lenjth of Time in Days. 
Fig. 12. Proteid-free Nitrogen, per cent, of dry material. 
until it reaches almost 10 per cent, in the last stage examined. The 
per cent, of ash in the hypocotyls rises gradually from the beginning 
of germination until the seventh day, when its increase is much more 
rapid. 
The weight of ash in the cotyledons decreases gradually until they are 
beginning to function as foliage leaves, after which it increases in amount. 
The ash content of the hypocotyls and roots rises gradually from the 
-- 
__< 
-- 
_—l 
- 
_ 
0 
/ 
2 
3 
4 
•5 
nyth ( 
6 
f Timt 
1 
? in Dc 
_ 
8 
tys. 
? 
IO 
// 
/a 
Fig. 13. Proteid-free Nitrogen, grams per ioo seedlings. 
beginning of germination to the last stage examined. The amounts are as 
one would expect when we consider the substratum in which the seedlings 
were grown. While the cotyledons were functioning as storage organs, 
and before the hypocotyls and roots could absorb to any degree for them¬ 
selves, the ash constituents of the cotyledons migrated downward. After 
the roots became active in absorption, the small amount of mineral matter 
absorbed was in part transported to the cotyledons, which were now 
dependent upon the roots for their water supply. 
