GERANIUM. 



105 



9:1 for Chamaenerium. When a flower of rose or of fireweed in a vial was 

 paired with rose flowers on the bush, the latter yielded 85 visitors to 49 for 

 the first and 7 for the second. When Rosa as the standard competed with 

 Aquilegia, the latter received nearly twice as many visitors and more than 

 twice as many visits, but when both were in the form of bouquets, the num- 

 ber of visitors and visits to the rose was thrice as great. This exception to 

 the general rule for standard and bouquet was due chiefly to the reversal 

 of the behavior of Bombus juxtus and the greater abundance of Prosopis. 

 The success of Mertensia sibirica in securing nearly four times as many 

 visitors as the rose was the result of the constant preference of Andrena 

 madronitens and Osmia phaceliae for it, all the other species choosing the rose. 

 The small number of visitors for Mertensia alpina is partly to be explained 

 by its being removed a long distance from its native habitat in terms of 

 climate and vegetation. 



Competition with normal and mutilated Aquilegia. — In this 

 experiment were employed 50 normal flowers of the rose and columbine, 

 and 10 flowers of each of the three kinds of mutilation. In addition, a 

 pile of loose petals 6 inches in diameter was placed on the ground. The 

 period of observation was one hour, 9 h 15 m to 10 h 15 m , July 13. 



Table 72. — Competition of Rosa with normal and mutilated Aquilegia. 



While the rose was more attractive to Bombus occidentalis, Andrena 

 crataegi and Megachile w. calogaster, the greater number of visitors of 

 B. juxtus gave the preference to the columbine. The mutilations were 

 relatively more visited than the normal flowers, this exception. to the rule 

 for decorollate flowers being explained by the bright-colored stamen mass 

 and the blue color of the sepals. 



GERANIUM. 



Comparison. — The flowers of Geranium caespitosum and G. richardsoni 

 are almost identical except for the color, the former being pink-purple and 



