XXI THE AGE OF, COMPOSITE 241 



but this is a point that has not yet been investigated. Nor can we 

 altogether exclude the chance of the achenes having in some cases 

 been transported unharmed to Hawaii in a bird's stomach. The 

 possibility of this has been above implied in the case of Artemisia ; 

 and it is pointed out in Chapter XXXIII. that pigeons in Hawaii 

 feed sometimes on the achenes of Compositse. The Hawaiian 

 goose (Bernicla sandwicensis) lives, according to Mr. Dole, on 

 Sonchus asper, an introduced plant, as well as on berries (Wilson's 

 Aves Hawaiiensis). There are numerous references of this nature 

 in books about birds, and it should always be remembered that 

 birds in pecking at the fruit-heads scatter the seeds on their 

 feathers. (See Note 6^^ 



From the foregoing remarks it may, I think, be inferred that 

 the achenes of the ancestors of the original Composite genera of 

 the Pacific islands were in all probability not unfitted for transport 

 by birds, more especially in their plumage. Some of my readers, 

 however, may express a doubt as to whether birds likely to disperse 

 seeds would be found in any numbers at the great heights where 

 some of the continental Compositse occur. But it is well known 

 that birds of the grouse and partridge family frequent high levels 

 in continental regions over much of the globe. Arborescent Com- 

 positae are found at heights of 10,000 to 14,000 feet on the 

 mountains of Central Africa ; and it should be noticed that Sir 

 Harry Johnston observed " francolins " on the slopes of Ruwen- 

 zori up to 13,000 feet [Uganda Protectorate, vol. i ; Trans. Linn. 

 Soc. Bot., Ser. II. vol. 2). Sir Martin Conway in the Bolivian 

 Andes found geese, ducks, gulls, snipe, &c., numerous in suitable 

 places up to 1 7,000 feet {Journ. Roy. Geogr. Soc, 1 899) ; whilst 

 geese and teal were noticed by Sir Joseph Hooker and others at 

 elevations of 17,000 feet in the mountains of Tibet (Hooker's 

 Himalayan Journals; Journ. Linn. Soc. Bot., vol. 35, p. 147). 

 These are all birds, as shown in Chapter XXXIII., that are likely 

 to disperse plants, and probably none more effectually than the 

 goose, of which Hawaii possesses a particular variety or species. 

 It may be remarked that geese, ducks, gulls, and other birds use 

 Cotula plumosa in Kerguelen for making their nests (Dr. Kidder 

 quoted by Mr. Dixon in his book on Birds' Nests). 



Sea-birds were probably the principal agents in carrying the 

 achenes of the early genera of the Compositse to Hawaii. Dr. 

 Hillebrand attached importance to the tropic-bird (Phaethon) in 

 the distribution of species (Introd., p. 30) ; and since these birds 

 breed at the crater of Kilauea in Hawaii, 4,000 feet above the sea, 

 VOL. II R 



