FLOWERS OF IMPA TIENS FULVA 151 



The agents of pollination in the vicinity of Philadelphia seem to 

 be chiefly bumble-bees and humming-birds. Bennett says he never 

 saw the flowers visited by insects. He quotes a curious old work, 

 "New England's Rarities discovered in Birds, Fishes, Serpents, and 

 Plants of that Country," by John Josselyn, Gent., London, 1675, in 

 which occur a drawing and a description of apparently Impatiens fulva 

 under the title of the Humming-Bird Tree. Dr. Macfarlane reports 

 stands of Impatiens fulva on Peak's Island and also on Mount Desert, 

 Maine, that were regularly worked over by a group of humming-birds. 

 Bees were not often seen to visit these flowers. In the Philadelphia 

 vicinity, humming-birds may frequently be seen visiting the flowers, 

 but the most persistent visitors seem to be bumble-bees. Smaller bees 

 and flies may sometimes be seen, but the bumble-bees are found visiting 

 flower after flower in continuous succession. The bee approaches the 

 flower as it hangs upside down, alights upon the broad lamina of the 

 petals and makes its way back to the inside of the spur, brushing its 

 back against the mass of stamens above. Bees emerging may be seen 

 to have their backs covered with pollen. The same day the flower 

 opens, or on the succeeding day, the mass of stamens falls away leaving 

 the pistil exposed in the flower. These detached whorls of stamens 

 are to be found lying about. A bee subsequently making its way mto 

 the flower must brush its back against the expanded stigmatic surfaces. 

 Mtiller (36) gives a similar account of pollination. Not infrequently bees 

 may be seen alighting upon the outside of the spur and making their 

 way to a point on the outside near the nectary, then on leaving to visit 

 another flower in the same manner. I have occasionally found small 

 flies working over the flowers in the same way, the flowers visited some- 

 times showing perforations and sometimes none in the spur. Only a 

 minority of the bees visited the flowers in the above manner, but the 

 bees following this method were not seen to enter the spur through the 

 open end. It was not determined whether the bees following this 

 method were a species different from those entering through the mouth 

 of the spur. Trelease (48) reports observation of this occurrence. He 

 determined that the bees did not make this perforation but merely took 

 advantage of perforations already existing. 



The method of polhnation described for fulva applies also for pallida 

 and sultani. Somewhat different methods are reported for other species. 

 In /. noli-tangere, according to Knuth, (26) the pistil protrudes between 

 the staminal processes and so may be poUinated. In 7. parviflora 

 and / balsamina the same mechanism is reported (Knuth 26). In I. 



