L909] Graenicher, Wisconsin Flowers and Their Pollination*. 35 



The blue flower shows about the same percentage of long- 

 tongued bees (eutropous) as the white, and even a greater per- 

 centage of short-tongued (allotropous) visitors, and this does not 

 agree with the theory of color preference. 



Tube length 3 mm. 

 I yellow (Rudbcckia hirta), and 2 blue (Aster puniceus and 

 A. Imvis, each with blue rays, and a yellow disk). 



Allotr. Hemitr. Eutr. 



Yellow 31.2 54.5 14.3 



Blue 20.7 60.4 18.9 



In this case the blue flowers have a somewhat larger percent- 

 age of long-tongued bees (18.9), but if we consider each of the 

 blue species separately we find 15.6% eutropous visitors in A. 

 puniceus and 22.2% in A. Icrvis. The blue A. puniceus agrees 

 more closely with the yellow Rudbcckia hirta than with the blue 



A. lirz'is. 



Tube length 4 mm. 



1 yellow (Rudbcckia laciuiataK and 1 purple flower (Aster 

 novas-anglke with purple rays, and a yellow disk). 



Allotr. Hemitr. Eutr. 



Yellow 9.1 59.1 31.8 



Purple 6.5 63.0 30.5 



There is a very slight difference between the two, and of the 

 most interest is the fact that the figures for the eutropous (long- 

 tongued) insects are about the same in both species. 



Tube length 4y 2 mm. 



2 yellow (Hclianthus strnmosus, and H. giganteus), and 1 

 purple (Biipatoriuin purpureum). 



Allotr. Hemitr. Eutr. 



Yellow 13.0 49.7 37.3 



Purple 7.6 69.8 22.6 



Here in the vellow flowers the long-tongued bees (37-3%) > 

 outnumber those 'in the purple flower (22.6) to a considerable ex- 

 tent, and this is just the opposite of what might be expected ac- 

 cording to the theory of color preference. 



Tube length 5 mm. 



I yellow (Heliopsis scabra), and 1 purple species (Liatris 



spicata). 



Allotr. Hemitr. Eutr. 



Yellow 23.8 47.6 28.6 



Purple 4.3 60.9 34.8 



