A STUDY OF GRASS SEED 163 



examination. Record the name of the grass in the column 

 of that sample number for classification. 



Spread the sample out on a blank piece of paper and make 

 a study of it for purity. Separate the sample into the follow- 

 ing groups : grass seed true to name ; seed of other grasses ; 

 weed seeds ; foreign matter. Weigh each group and record 

 its weight and per cent on the blank form in the column for 

 that sample number. Weigh accurately to one tenth of 

 one gram. Quantities less than one tenth of one gram 

 may be indicated as " trace." All the groups under purity 

 should total 100 per cent. 



Separate from the sample one hundred seeds true to 

 name and make a germination test as described in Ex. 

 39. Record the data of the germination test in Ex. 39. 

 Record the per cent of germination on the blank form. 

 From the data recorded on the blank form compute the per 

 cent of the sample that will grow and that is true to name. 



