Aug. 14, 1916 



Agricultural Value of Impermeable Seeds 



765 



Over 90 per cent of the impermeable seeds were viable in every case, 

 except the lot of seed of Chamaecrista nicitans. In most cases 100 per 

 cent were viable. The average percentage of viability of the impermeable 

 seeds was invariably greater than of the seeds which softened within 

 six days. The difference ranged from 1 per cent to over 50 per cent — 

 the latter with 3-year-old white-clover seed — and in general increased 

 with the age of the seed. 



RATE OF SOFTENING OF IMPERMEABLE SEEDS WHEN KEPT IN WET BLOTTERS 



Table III shows the average rates of softening of seeds which had re- 

 mained impermeable after 10 days in wet blotters. These seeds were kept 

 in wet blotters for three years. 



Table III. — Rate of softening of impermeable seeds -when kept in wet blotters 



1 All hand-gathered lots of seed were gathered and hulled by hand a few days before the beginning of 

 the tests. Commercial lots were of uncertain age, probably in most cases a little less than i year old. 

 a After 15 days. 



i. Less than 10 per cent of the seeds of red clover, alsike clover, white 

 clover, and sweet clover which remained impermeable after 10 days 

 softened in one month; and from about one-third to a little over one- 

 half of them softened in three years. 



2. Nearly all of the impermeable seeds of alfalfa, hairy vetch, okra, 

 and crimson clover which remained after 10 days softened in one year 

 in wet blotters, but a very few of all except crimson clover remained 

 impermeable after three years. There is a marked contrast in this respect 

 between these species of plants and those named in the preceding 

 paragraph. 



3. The impermeable seeds in hand-gathered lots of alsike-clover seed 

 and alfalfa seed softened much more rapidly than the impermeable seeds 



