298 



Bulletin 312 



Bolley found the following amounts of hard seed in samples of different 

 agricultural seeds : 



TABLE I 



Record number of sample and kind of seed 



Alfalfa No. 464 . . . 

 Alfalfa No. 474. . . 

 Alfalfa No. 1165. . . 

 Alfalfa No. 1210. . . 

 Alfalfa No. 1420. . . 

 Alfalfa No. 1434. . . 

 Alfalfa No. 1590. . . 

 Alfalfa No. 1594. . . 

 Red clover No. 11 56 

 Red clover No. 11 59 

 Red clover No. 1191 

 Red clover No. 1192 

 Alsike No. 1435 



Number 



germinated 



after 



lo-day 



test 



Number 

 hard at 

 end of 

 10 days 



45 

 50 

 12 

 40 

 9 

 25 

 18 

 18 

 15 

 51 

 18 

 16 

 15 



MATERIAL AND METHODS 



The seeds used in the following experiments were obtained from many 

 sources. Some, as stated above, were furnished by the Illinois Experi- 

 ment Station and some by the Bureau of Plant Industry of the United 

 States Department of Agriculture; other seeds were gathered in and 

 about Ithaca; while still other lots were obtained from seedsmen and from 

 laboratory stock. 



The acid used was either C. P. sulfuric or commercial sulfuric of about 

 1.84 specific gravity. The concentrated acid was used for all the tests. 

 The other apparatus used was such as is found in any ordinary laboratory. 



When there is only a small amount of seed to be treated, such as the 

 seed from a single head of clover or from a single clover plant, amounting 

 to not more than a few hundred seeds, the following method may be 

 employed : 



Place the seed in a small homeopathic vial or test tube. Pour on the 

 seed a quantity of concentrated sulfuric acid equal to about five or six 

 times the volume of the seed. Stir the mixture thoroughly with a stirring 

 rod until all seeds are completely covered with the acid. Allow to stand 

 for the time desired at ordinary room temperature. (See tables and 

 conclusions for the length of time.) At the end of this time allow water 

 from a faucet to run into the vial or test tube until it is nearly full, then 

 quickly pour the entire contents into a strainer (an ordinary tea strainer 

 is used for this purpose) and wash quickly with water. (If this method 



