108. REPORT— 1876. 



marked, we find a great pieponderauce of small, green, or otherwise inconspicuous 

 flowers, indicating that inly such plants have been enabled to flourish there as are 

 independent of insect-fertilization. In the Galapagos (which are perhaps even 

 more deficient in flying insects than Juan Fernandez; this is so striking a feature 

 that Mr. Darwin speaks of the vegetation as consisting in great part of " wretched- 

 looking weeds,'" and states that " it was some time before he discovered that almost 

 every plant was in flower at the time of his visit." He also says that he " did not 

 see one beautiful flower " in the islands. It appears, however, that Compositte, 

 Leguminosse, Rubiacefe, and Solanaceae form a large proportion of the flowering 

 plants; and as these are orders which usually require insect-fertilization, we must 

 suppose, either that they have become moditied so as to be self-fertilized, or that 

 they are fertilized by the visits of the minute Diptera and Hymenoptera, which are 

 the only insects recorded from these islands. 



In Juan Fernandez, on the other hand, there is no such total deficiency of showy 

 flowers. I am informed by Mr. Mcjseley tliat a variety of the Magnoliaceous winter- 

 bark abounds and has showy white flowers, and that a Biguoniaceous shrub witli 

 abundance of dark blue flowers was also plentiful ; while a white-flowered Liliaceous 

 plant formed large patches on the hill-sides. Besides these there were two species 

 of woody Oompositse with conspicuous heads of yellow blossoms, and a species of 

 white-flowered myrtle also abundant ; so that, on the whole, flowers formed a rather 

 conspicuous feature in the aspect of the vegetation of Juan Fernandez. 



But this fact — which at flrst sight seems entirely at variance with the view we 

 are upholding of the important relation between "the distribution of insects and 

 plants — is well explained by the existence of two species of humming-birds in 

 Juan Fernandez, which, in their visits to these large and showj' flowers, fertilize 

 them as efl'ectually as bees, moths, or butterflies. Mr. Moseley informs me that 

 " these humming-birds are e.itraorilmarili/ abundant, every tree or bush having one 

 or two darting about it." He also observed that " nearly all the specimens killed 

 had the feathers round the base of the bill and front of the head clogged and 

 coloured yellow with pollen." Here, then, we have the clue to the perpetuation 

 of large and showy flowers in Juan Fernandez ; while the total absence of hum- 

 ming-birds in the Galapagos may explain why no such large-flowered plants have 

 been able to establish themselves in those equatorial islands. 



This leads to the observation that many other gi-oups of birds also, no doubt, aid 

 in the fertilization of flowers. I have often observed the beaks and faces of the 

 brush-tongued lories of the Moluccas covered with pollen ; and Mr. Moseley noted 

 the same fact in a species of Artamus, or swallow-shrike, shot at Cape York, show- 

 ing that this genus also frequents flowers and aids in their fertilization. In the 

 Australian region we have the immense group of the Meliphagidte, which all 

 frequent flowers; and as these range over all the islands of the Pacific, their presence 

 will account for a certain proportion of showy flowers being found there, such as 

 the scarlet Metrosideros, one of the few conspicuous flowers in Tahiti. In the 

 Sandwich Islands, too, there are forests of 3fetrosideros ; and Mr. Charles Pickering 

 writes me, that they are visited by honey-sucking birds, one of which is captured 

 by sweetened bird-lime, against which it thrusts its extensile tongue. I am also 

 informed that a considerable number of flowers are occasionally fertilized by hum- 

 ming-birds in North America ; so that there can, I think, be little doubt that birda 

 play a much more important part in this respect than has hitherto been imagined. 

 It is not improbable that in Tropical America, where the humming-bird family is 

 so enormously developed, many flowers will be found to be expressly adapted to 

 fertilization by them, just as so many in our own coimtry are specially adapted 

 to the visits of certain fomilies or genera of insects. 



It must also be remembered, as Mr. Moseley has suggested to me, that a flower 

 which had acquired a brilliant colour to attract insects might, on transference to 

 another country, and becoming so modified as to be capable of self-fertilization, 

 retain the coloured petals for an indefinite period. Such is probably the explana- 

 tion of the Pe/arr/oniiim of Tristan d'Acunha, which forms masses of blight colour 

 near the shore during the flowering season; while most of the other plants of the 

 island have colourless flowers, in accordance with the almost total absence of winged 

 instcts. The presence of many large and showy flowers among the indigenous 



