74 SEEDS AND FRUITS 
PER CENT OF GERMINATION FOR EACH OF 6 YEARS 
OF STORAGE 
Seed. lyr. 2 yr. 3 yr. 4 yr. 5 yr. 6 yr. 
Wheaten. «222 pahkehy ivan peewee 80 82.3 | 77.3 | 37 | 15 6 
OATS) acs o65-.240e oer esate 6 pete 90.2 | 93 78.2 | 67 | 54 29.5 
Barley ec chicnaahseccnyedidnn cc Seed Saintes 97 91 78.5 | 36 19.5 | 7.5 
PCBS sien 4c area ees paresa S dylaceoo is unseen 94 95 88 64 | 64 6 
DAK anoe state pact ng ts uatas 4d BONS 81 82 75 49 | 26 24 
Purity and the Analysis of Seeds 
The impurities of seeds consist of seeds of other species and of 
dirt, such as soil particles, chaff, hulls, and other plant fragments. 
In sowing impure seeds one can not estimate the amount of 
desirable seeds sown unless the percentage of impurities is pre- 
viously determined so that allowance can be made. Besides one 
is likely to sow the seeds of undesirable plants, which choke the 
crop and cause much trouble and expense in eradicating them. 
A small per cent of weed seeds is often a serious matter. For 
example, in sowing Grass seeds which contain only 1 per cent of 
weed seeds there is the possibility of 20 or more weeds to the 
square yard. Nobbe found enough weed seeds in a certain 
sample of Timothy seeds, if sown at the ordinary rate, to supply 
24 weeds to every square foot of land. Furthermore, in purchas- 
ing impure seeds, unless a deduction from the price is made for 
the impurities, one pays more than he should for the desirable 
seeds obtained. 
More impurities occur among the smaller agricultural seeds, 
as Grass, Clover, and Alfalfa seeds, than among the grains, al- 
though a few very bad weed seeds, such as those of Quack Grass 
(Agropyron repens), Cow Cockle (Saponaria Vaccaria), Corn 
Cockle (Lychnis Githago), and English Charlock (Brassica 
Sinapistrum), are common among the small grains. 
Seed Analysis. — A bag of seeds may be analyzed for two 
reasons: (1) to determine the percentage of the desirable seeds 
contained or to determine the percentage of impurities regardless 
of their kinds; and (2) to determine the kinds of impurities and 
the percentage of each present. In either case the determination 
is based upon the analysis of only a small sample, which is usually 
prepared by mixing well a handful or more of seeds taken from 
