104 GRASSES OF IOWA. 



Table No. VI shows the minimum, average and maximum 

 percentages of vitality and impurity for a large number of 

 grasses. The column headed "Days required" shows the 

 number of days required for all vital seed to germinate. "No." 

 indicates the number of tests from which the figures given 

 were obtained. These figures were compiled by Charles 

 Lathrop Parsons* and include most of the tests made up to 

 January, 1891. By comparing this table with table No. V, some 

 interesting facts are brought out. It will be noted that the 

 vitalities are much lower than the standard of table No. V. 

 For example, timothy is about 9 per cent lower, orchard grass 

 21 per cent, red top 28 per cent, and Kentucky blue grass over 

 50 per cent lower. These results are based on a large number 

 of tests in each case, as may be seen by referring to the first 

 column. 



Table No. VII was condensed from the results of tests pub- 

 lished by Prof. P. L. Harvey, t The seeds were germinat-d 

 in cloth pockets in a galvanized tray containing water in the 

 bottom. In noting these vitalities the reader must bear in 

 mind that the tests were continued for only fourteen days, and 

 that most grasses require a longer period for complete germi- 

 nation. This accounts for the large number of sound seeds 

 remaining at the end of the test. Of course, not all of them 

 would have germinated if the test had been continued, but it is 

 probable that part of them would have done so. 



•A Summary of American Seed Tests. Azrl. Science. 7: 541-545. 

 tGermlnatlon Experiments. Maine Agrl. Exp. Station, Ann. Report. 1888: 136- 

 137. (See pp. 143-147.) 



