8 DISTRIBUTION OF SEEDS AND PLANTS. 



in writing as a part of the permanent record. Approximately 25 per 

 cent of the seeds are purchased from surplus stocks grown the 

 previous year, and the remaining 75 per cent are grown under con- 

 tract for the Department during the current season, thus insuring 

 that the seeds shall be fresh and of strong vitality. 



HOW SEEDS AHE TESTED. 



All purchases are made subject to satisfactor}^ appearance, viability 

 (germination), and trueness to varietal name or type. The testing 

 of samples of seed to ascertain its viability is done by experts in the 

 Seed Laboratory of this Bureau, both before and after the shipment 

 of the bulk seed. When a consignment of seed is received at the 

 warehouse a small portion is taken from the middle and near the top 

 and bottom of at least one-fourth of all bags and thoroughl}^ mixed 

 to make a comi^osite sample, which is then sent to the seed laboratory. 

 From the sample 100 or 200 seeds are counted out and placed be- 

 tween moist blotters in a germinating chamber, which is really an 

 incubator fitted wdth automatic devices for keeping the blotters moist 

 and for regulating the temperature to suit the requirements of differ- 

 ent kinds of seed. At the end of a week or more, depending on the 

 kind of seed, the blotters are examined and the number of seeds 

 wdiich have sprouted are counted to determine the percentage of 

 germination. As the result of these tests many thousands of pounds 

 of vegetable and flower seeds which fail to meet the requirements of 

 the Department as to viability are rejected annually. Table II 

 and III show tlie average percentage of germination of all vegetable 

 tlie flower seeds purchased by the Department for distribution dur- 

 ing the past 11 and 10 years, respectively, and the viability of 

 so-called "commission" seeds ^ (vegetable-) purchased in the open 

 market, during the past 4 years. 



1 " C'ommission " seeds are u.-iually put up in packets and sent out to dealers for sale by 

 them on a commission basis, all seed not sold at the end of the season being returned to 

 the seed-packing house. 



-Purchase of "commission" seeds by agents of the Department have been confined to 

 vegetables, so that no data for flower seeds of this class are available. 

 [Cir. 100] 



