26 



PRODUCTIVE FARMING 



Exercise. — Identifying Weed Seeds. — The figures in 

 U. S. Farmers' Bulletins 260 and 382 will help to determine 

 the names of the weed seeds not known by the pupils. Let 

 students cut out the figures and paste them on a card for 

 quick reference. If the school has a collection of weed seeds 

 in small bottles (Fig. 14), they may now be used to help 

 identify the unknown seeds. 



Exercise. — To Compare Good and, Poor Lots of Grass 

 Seeds. — Take a piece of clean window glass and wet it with 



Fig. 12a. — Teacher showing the class how to examine a seed sample. 

 Fig. 126. — Seeds on the thumb, magnified through a reading glass. 



water. Spread on it a thin layer of blue-grass or of red-top 

 seeds. Hold the glass between you and the bright light. 

 Notice how many of the glumes or husks are hollow. Com- 

 pare in this way a good sample with a poor one. Note the 

 difference in the amount of chaff. 



Seed Analysis. — The methods of studying seeds outlined 

 in two preceding exercises may be called seed analysis. The 

 sieves mentioned before may also be used in analyzing a 

 sample of seed as well as in aiding in the cleaning of large 

 quantities. 



Seed Testing. — Another way to detect impurities in 

 seeds is by sprouting a sample of the seed and then observ- 



