New YorK AGRICULTURAL EXPERIMENT STATION. 347 
It may be remarked that the very large number of seeds of 
low specific gravities, that is of ungerminable seeds, is probably 
attributable to imperfect pollination. Other cultural conditions 
also exercise a marked influence on the specific gravity of seeds. 
For instance, the common field corn of New York State ranges 
in specific gravity up to about 1.15; but some of the corn of high 
protein content now being bred in the west ranges up to 1.25. 
It isa matter of common knowledge that wheat grown in northern 
Colorado is heavier than the same variety grown in the Mississippi 
valley. It has also been definitely proven by Wollny that the 
same variety may vary in specific gravity from year to year. That 
investigator’s determinations were made by the method of sam- 
ples, and consequently represent only averages for the whole 
amount of seed. While the optimum specific gravity of a variety 
grown under favorable conditions might not vary much, numerous 
conditions might enter in to bring it about that there might be 
a larger number of slightly inferior seed in one sample than in 
another. By this consideration the average specific eravity would 
be lower and yet the optimum specific gravity might remain 
unchanged. The suppositions are confirmed in the writer’s 
mind by his observation of grape seeds grown under different 
conditions; but figures are not at hand to support these state- 
ments. 
As to the range of specific gravity in the seeds of a number of 
cultivated crops, the Cruciferee range from about 1.21 down, let- 
tuce from 1.10, Solanacee from 1.12, onion from 1.18, carrot 
from 1.15, grapes from about 1.16, buckwheat from 1.23, and 
wheat, rye and naked leguminous seeds from 1.30 to 1.36 accord- 
ing to the variety. 
Renz concluded from his investigations that the seed of every 
kind of plant has in its natural ripe and fully developed condi- 
tion a specific gravity which varies only between certain limits, 
apparently meaning by this rather narrow limits. From this 
conclusion he makes the deduction that specific gravity can be 
used as a distinguishing character of the kind and quality of the 
seed. The writer’s observations tend to support the conclusion 
that specific gravity is a character of the variety but not a dis- 
tinguishing character. This last is for the reason that seeds of 
