BIRD-POLLINATED PLANTS 



75 



Fritz Miiller writes to F. Ludwig with regard ' to humming-birds and other 

 species as agents of pollination (Bot. Centralbl., Ixxi, 1897, pp. 301, 302), to the 

 following effect. 'Humming-birds, which constitute one of the most important 

 groups of pollinators, are on the wing in Brazil throughout the year. Their 

 activity in visiting flowers is far greater than would appear from accounts known 

 to me. I could almost believe that the list of flowers not visited by them would 

 be considerably smaller than a list of those that are visited. Even quite inconspicuous 

 flowers, such as those of the small Composite Buddleia brasiliensis and the little 

 green blossoms of Hohenbergia angusta, are visited by them. In the winter months, 

 when butterflies and bees are very rare (except the social species of Melipona and 

 Trigona), these birds are almost the only flower-visitors. Frequently (like the 

 largest of our bees, a Xylocopa) they steal the nectar by boring, e. g. in Abutilon 

 and the beautiful Jacaranda (digitaliflora .?).' 



The flower-visiting humming-birds are often so like the hawk-moths, which 

 seek out the same flowers, 

 as to be mistaken for them : 

 * Several times,' says Bates 

 (' The Naturalist on the River 

 Amazon,' London, ed. 1892, 

 p. 94), 'I shot by mistake a 

 humming-bird hawk-moth in- 

 stead of a bird. This moth 

 (Macroglossa Titan) is some- 

 what smaller than humming- 

 birds generally are; but its 

 manner of flight, and the way 

 it poises itself before a flower, 

 whilst probing it with its pro- 

 boscis, are precisely like the same actions of humming-birds. It was only after 

 many days' experience that I learnt to distinguish one from the other when on the 

 wing' (cf. Fig. 11). 



Fritz IMiiller made the same observation in Brazil. He wrote as follows to his 

 brother Hermann : ' A large bush of a beautiful sky-blue Salvia, that occurs here, 

 and which is now blooming in my garden, is visited by a Macroglossa, which has 

 such a deceptive likeness to a humming-bird in form, colour, and mode of flight, that 

 my little ones described it to me as a remarkable six-legged humming-bird.' 



The only humming-bird that occurs in North America ^ is Trochilus colubris, 

 which is best known as the pollinator of Impatiens fulva. According to Asa Gray, 

 Beal, Robertson, and Trelease, it also pollinates many other flowers, such as Tecoma 

 radicans, Hibiscus lasiocarpus, Lobelia cardinalis, Gossypium herbaceum, Fuchsia, 

 Bignonia, Passiflora incarnata, Aesculus parviflora, and others, as well as acclimatized 

 European species, such as Scrophularia nodosa, Trifolium pratense, and Oenothera 



Fig. II. Hiiinniing-Bird and Huinmingbiyd Hawk-moth 

 (Herm. Muller, after Bates.) 



' [This statement is incorrect. Newton (' A Dictionary of Birds,' ed. 1 899) states (p. 448), 

 ' In the north-west Selatophorus riifus in summer visits the ribes-blossoms of Sitka.' And again 

 (p. 450), ' Seventeen species have been enrolled in the fauna of the United States . . .' Tr.] 



