- 40 - 
p. 31 J Cross-pollination of flax by bees increased the 
yield, as measured by quantity of grain, 28.57 percent; as 
measured by weight of seed, 31.01 percent and raised the abso- 
lute weight of 1000 grains from 5.0372 to 5.1329 gm. Consequently, 
the development of seeds with se]f -pollination proved to be some- 
what depressed. Usually with a smaller quantity of seed and fruit 
they grow larger in size; in the given case the reverse was observed — 
the resultant yield with cross-pollination was higher in respect 
of both -quantity and quality. 
On the open plot where the number of visits was only 67.8 
percent of the number of flowers, the increase of the yield of 
flax proved to be less significant; the number of grains from 
500 bolls rose from 2688 to 3050, that is 13.47 percent; their 
weight rose from 13.5934 to 15.8878 gm. or 16.88 percent; the 
weight of 1000 grains rose from 5.0576 to 5.2095 gm. 
Radish 
Crane, U. B., and Mather, K. 
1943. The natural cross-pollination of crop plants with particular 
reference to the radish. Ann. Appl. Biol. 30: 301-308. 
p. 307: As the radish is self-incompatible each plant must 
receive pollen from another plant to produce seed. In these experi- 
ments the pollen could come from a sister plant of the same variety 
or from a plant of a different variety. As shown in Figs. 4-6, 
25 hives of bees were maintained close to the experiments. Thus, 
the bee population was much higher than in most cases where crops 
are grown commercially for seed, and the number of bees visiting 
the plots during the flowering period was extremely large. The 
seed crop was heavy throughout the plots, indicating that cross- 
pollination had been effectively carried out. 
Kremer, J. C. 
1945. Influence of honey bee habits on radish seed yield. Mich. Agr. 
Expt. Sta. Quart. Bui. 27: 413-420, illus. 
p. 419: Figure 4 illustrates a typical example of the effective 
radius of commercial bee yards located in a radish seed area, where 
radish seed fields were located without regard or knowledge of their 
existence. 
All the fields located within the circles or the 2-mile radius 
produced from 400 to 450 pounds of seed per acre, while those on 
the border of this radius or beyond averaged 200 to 300 pounds of 
seed per acre. One field located within the flying radius of two 
of these bee yards averaged 600 pounds per acre. No other colonies 
