New YorK AGRICULTURAL EXPERIMENT STATION. 339 
medium specific gravity was best for planting. It was also 
richest in oil. , 
Seulen recommends floating off light seeds and foreign matter 
from garden seeds which are to be planted, by immersing them 
in water. Other persons who have reported favorably on the 
practice of seed selection according to specific gravity are Church, 
Dietrich and Trommer, as cited by Wollny. 
Especially timely is the present investigation in view of the 
fact that a well known English seed firm has recently advertised 
that they are perfecting a method of selecting seeds according to 
specific gravity. This firm already advertises to apply the method 
of selection by salt solutions to the selection of forage roots to be 
used for mothers. 
PREVIOUS INVESTIGATIONS NOT FAVORABLE TO THE SPECIFIC GRAVITY 
METHOD. 
Mention will now be made of some of the investigations which 
have led experimenters to assert that the method of specific 
gravity is of little or no applicability in practice: 
Hellriegel separated from a lot of barley, kernels of specific 
gravities 1.255, 1.205 and 1.15, all of which weighed from 34 to 
36 milligrams each. The experiment was repeated a second sea- 
son, in this case selecting seeds lying between 36 and 38 milli- 
grams. There was no noticeable difference between the plants 
from the different seeds and the investigator concludes that 
specific gravity has no considerable effect on the vigor and size 
ef the plant, either as a seedling or as a mature plant. 
Marek re-investigated the method of seed selection according 
to specific gravity by exact methods. His conclusion is that 
specific gravity is no general criterion of the quality of the seed, 
and that only when the more intimate relations of the composi- 
tion of the seed to its specific gravity are known can the latter be 
accepted as a standard of judgment of quality. 
Nobbe has reviewed the subject and has also reached the con- 
clusion that the practice is of little value in agriculture. 
Willard, Clothier and Weber applied the method of specific 
gravity to the selection of seed corn, but without positive results. 
Wollny has critically reviewed the subject and reaches the 
conclusion that specific gravity is of no account in seed selection. 
