DEPAETMENT REPORTS. 13? 



Some experiments made in 1881 give a different result. 



Seeds were selected in lots of 50, 250 of dark and 250 of light-colored, 

 with the following result: Dark germinated 240, light 244. 



This illustrates the folly of attempting to draw general conclusions from a 

 few experiments. 



In the spring of 1881 two beds, each about 6 x G feet, were sown to red 

 clover. In one, dark seeds only were sown ; in the other, light seeds. These 

 were picked from the same lot of seeds. For a time, at first, we thought the 

 dark seeds did the best, but after a little no difference could be seen. A single 

 plant in the bed sown to dark seeds was of unusually dark color. The leaves 

 were thick, the flowers dark, the stems smooth and the plant vigorous. 



DO BUMBLE BEES BEKEFIT BED CLOVER? 



From time to time I have seen reports asserting the great value of these bees 

 in aiding clover blossoms to set seeds. Bumble bees have been exported to 

 Australia for the purpose of inducing clover to seed more freely. 



Without question, pollen of a flower gets freely on the stigma of the same 

 flower, but this does not make it certain that pollen from another would not 

 produce better results. 



For six years past I have had some reliable students experimenting on this 

 subject. The results are yet quite variable and unsatisfactory. 



In the first year, the heads covered when young with sacks of muslin, 

 yielded about two-thirds as many seeds as those left uncovered. In the second 

 year, four heads covered before flowering yielded 18, 30, 38, 41 seeds respect- 

 ively ; four heads of the same age, left uncovered, yielded, respectively, 46, 54, 

 43, 57 seeds. In the third year, 31 heads of the first crop were covered as 

 above. Only one yielded seeds, and that bore seven. Thirty-one heads of the 

 same age, uncovered, yielded 11, 12, 2, 35, 40, 21, 3, 1, 22, 15, 15, 20, 16, 4, 

 29, 3, 25, 8, 15, 22, 24, 28, 41, 10, 22, 13, 18, 18, 10, 12, 10, an average of 17 

 seeds per head. In the third year for the second crop of clover, 9 heads were 

 uncovered, and yielded 36, 51, 45, 58, 15, 26, 47, 31, 28, an average of about 

 37t} seeds to the head. Eleven heads covered yielded no seeds. In the cases 

 above given the heads tied in sacks were allowed to fall to the ground, which 

 may have damaged them to some extent. The shade of the sacks may also 

 have been a hindrance. 



In the fourth year, on the first crop eight heads were tied up and the sacks 

 tied to stakes to keep the heads from the ground. These heads produced no 

 seeds. The flowers of some of the same age uncovered were examined imper- 

 fectly, and the student says three-fifths of them produced seeds. 



On tlie fifth year, 1881, seven young heads of the first crop were covered. 

 One head only produced seed, and that one, three. This head, when in 

 flower, was seen to have a small insect of some sort crawling over it. Eight 

 heads of the same age not covered were examined. One of these contained 

 15 seeds; each of the other seven contained from 20 to 52 seeds. 



The covered heads of the second crop and the uncovered heads yielded 

 about the same number of seeds as did those of the first crop. 



On the sixth year, 1882, two fine bunches of the first crop, apparently 

 alike, were covered with mosquito netting. No insects were seen about 

 either, except what are mentioned below. 



On June 29th a bumble bee was placed inside of one netting and seen to 

 work on the flowers. 



