260 PASTORAL AND AGRICULTURAL BOTANY 



Apparatus for Seed Testing. Most seed control stations have elabo- 

 rate apparatus, which is used in the scientific study of the seed control 

 problems. Such apparatus is described in various bulletins and text- 

 books enumerated below and need not be described in detail here. The 

 following apparatus is recommended for use in making purity and germina- 

 tion tests. 



PURITY TESTS 



1. A chemical balance, weighing up to 100 grams and sensitive to i 

 milligram, with accurate metric weights. 



2. A seed mixer and sampler. 



3. A nest of small copper sieves. 



4. A vertical air-blast seed separator. 



5. A reading glass mounted on a stand. 



6. A hand lens, magnifying from 10 to 16 diameters. 



7. A standard dissecting microscope. 



8. Botanical forceps and dissecting instruments. 



9. An authentic collection of the seeds of the principal weeds and 

 cultivated plants. 



GERMINATION TESTS 



1. Standard, or Semper's germinating chambers, equipped with low- 

 temperature thermostats and thermometers. 



2. Blue blotting paper and canton flannel. 



3. Sterilized sifted sand and shallow greenhouse flats. 



4. Forceps. 



5. Blank Forms for Record and Report. 



Ordinarily such elaborate apparatus is not necessary for the simple 

 experiments that a farmer ought to make in testing his seeds. He ought 

 to have two dissecting needles, a small scalpel, a pair of forceps, a hand 

 lens magnifying 16 diameters, a small chemical balance, a small graduated 

 cylinder holding about 100 cubic centimeters, a dinner plate, a small 

 bell jar, and several mats made by sewing squares of blotting paper be- 

 tween two pieces of canton flannel. 



PRACTICAL SEED TESTING 



There are four fundamental points to be considered in practical seed 

 testing. They are: 



