166 JOHN H. LOVELL 



in 1908. On August 14 of that year, the vines were in full 

 bloom, and there were present many workers of Bombus terricola, 

 which perforated the flowers as fast as they matured — so far as 

 I could discover not a single blossom escaped. The holes were 

 all on the under side of the calyx on the left hand side, which 

 may be explained by the fact (also observed by Muller'i) that 

 the more powerful bees almost invariably alight on the left ala. 

 The honey-bees promptly discovered the holes and used them 

 most diligently for extracting the nectar. There was no pretence 

 on the part of either honey-bees or bumblebees of making nor- 

 mal visits. The absence of bees from the flowers of the scarlet 

 runner does not, therefore, prove that their brilliant hue is of 

 no advantage, or that an agreeable odor is required, for it is only 

 necessary to render the nectar easily accessible by punctures to 

 induce the visits of bumblebees and honey-bees in great numbers. 



The correlation existing between the accessibility of nectar 

 and the number of honey-bees present is also most instructively 

 shown by the inflorescence of red clover, Trijolium pratense L. 

 The flowers are pollinated chiefly by bumblebees, which are 

 frequent visitors, and in their absence are largely sterile. An 

 historical illustration is the well-known experience of the agri- 

 culturists of New Zealand, in which country at the time of its 

 discovery there were neither honey-bees nor bumblebees. In 

 consequence the yield of seed did not become commercially 

 profitable until in 1855, when about one hundred bumblebees 

 were imported from Europe. 32 



The nectar of red clover is secreted at the base of a tube a 

 little over 9 mm. in length, where it is beyond the reach of the 

 tongue of the honey-bee. This has occasioned much regret 

 among bee-keepers, for the flowers not only secrete nectar very 

 freely but the quantity is not greatly affected by weather con- 

 ditions. Repeated attempts have been made to develop a strain 

 of red clover bees, but the gain in tongue length has invariably 



31 Mliller, H., " Fertilization of Flowers," p. 216. Both honey-bees and bumble- 

 bees almost invariably alight on the left ala. The reason for this is that the spirally 

 coiled carina closes the entrance beneath the standard on the right hand side. 

 Usually the alae stand apart, but when one occasionally overlaps the other, honey- 

 bees alight on the center. Bumblebees visit the flowers of the common, garden 

 bush beans in a similar manner. 



"Knuth, P., " Handbook of Flower Pollination," translated by J. R. Ainsworth 

 Davis, 2:292. Jarvis, P. D., " Bumblebees that Fertilize Red Clover," Rep. Ent. 

 Soc. Ont., 36:128. Graenicher, S., " New Zealand's Experience with the Red Clover 

 and Bumblebees," Bull. Wis. Nat. Hist. Soc, 8:166. 



