50 IOWA ACADEMY OF SCIENCE 



COUNT FOB BLACK LOAM WITH GRAVEL — SECOND CROP. 



Magnitudes 39 40 41 42 43 44 45 46 47 48 49 50 51 52 54 55 56 



Frequencies 1 1 1 1 1 1 1 2 2 1 3 5 3 2 4 2 8 



Magnitudes .. ; 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 



Frequencies 2 44414218183435 10 14 



Magnitudes 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 



Frequencies 6 6 3 3 2 9 4 14 1 5 2 8 2 6 5 6 4 4 



Magnitudes 92 93 94 95 97 99 100 101 102 104 105 106 107 108.109 112 



Frequencies 593462 7 5 3 8 4 9 3 4 5 3 



Magnitudes 113 115 118 119 120 121 122 123 124 125 126 127 128 



Frequencies 8 2 4 3 7 2 4 1 7 6 6 5 1 



Magnitudes 129 130 133 135 136 137 138 139 140 141 142 143 144 



Frequencies 2 1 3 2 6 4 4 1 2 2 2 2 4 



Magnitudes 145 146 148 161 162 170 171 176 183 



Frequencies 1 3 1 2 1 2 1 2 1 



An additional study was made* in the fall of 1910 ; the flowers of 983 

 heads were counted. The material was taken from various soils, and lo- 

 calities, in the neighborhood of Jefferson, Iowa, during a period ex- 

 tending from June to September. 



According to the results of this study, variation of clover heads 

 between fifty-three and sixty-eight flowers each, is quite irregular, but 

 from sixty-eight to eighty-three it is very smooth; in fact this with 

 small breaks at eighty-three and again at eighty-eight, reached to the 

 central mode at ninety-eight. The drop on the other hand, is much 

 more irregular. 



COUNT FOR FLOWERS IN HEADS OF RED CLO\^R. 



Magnitudes 54, 59, 60, 61, 64, 65, 67, 68, 70, 71 



Frequencies 7, 4, 5, 3, 2, 1, 11, 4, 15, 1 



Magnitudes 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83 



Freuencies 6, 3, 2, 13, 16, 9, 8, 15, 17, 9, 30, 7 



Magnitudes 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95 



Frequencies 18, 25, 14, 24, 16, 15, 17, 40, 45, 32, 24, 32 



Magnitudes 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107 



Frequencies 22. 27, 24, 37, 25, 11, 16, 20, 36, 16, 22, 18 



Magnitudes 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 119, 120 



Frequencies 10, 28, 16, 30, 22, 1, 13, 21, 5, 21, 1, 9 



Magnitudes 121, 122, 123, 124, 125, 126, 128, 130, 131, 135, 136, 138 



Frequencies 8, 2, 3, 3, 9, 2, 2, 3, 2, 4, 3, 1 



The range extended from fifty-three to one hundred forty-two flow- 

 ers. The mean, as derived from the frequencies shown is 90.44 flowers. 



^By Miss Wennholz and Miss Mills. 



