380 Floristik, Geographie, Horticultur etc. 



structures that now serve a purpose for which they were not originally 

 intended". The relationship of littoral to inland plants (Chaps. XIV 

 to XVI) is dealt with by discussing the littoral and inland species of 

 22 genera. In 7 genera {Vigna, Premna, Canavalia, Guettarda , 

 Erythrina, Sophora , Ochrosia) the inland species are regarded as 

 deVived from the littoral species; in 3 genera Etigenia, Drymisper- 

 mum, Acacia) the coast species are derived from the inland flora; 

 and in twelve the development has been more or less independent. 

 Schimper's view that the individuality of the mangrove-formation 

 is due to special adaptation is met by the Suggestion that the man- 

 grove swamp is "the remnant of an ancient flora widely spread 

 during an age when vivipary was not the exception, but the rule". 

 Ä chapter is given to the "Stories of Afselia hijuga , Entada scan- 

 dens, and Cesalpinia bonducella''' the argument being that these and 

 most of the othe;- littoral Legmninosae have originally come from 

 America; it is also shown that the seeds of coast plants float while 

 as a rule those of inland plant sink, and this is ascribed to the 

 influence of Station on the ripening seed. 



The inland Plants of the Pacific Islands are also considered 

 from the point of view that the Fijian, Tahitian, and Hawaiian 

 groups of islands are the chief centres of distribution. "After dis- 

 cussing the relative sizes, the altitudes, and the climates of the three 

 archipelagoes , it is shown that Hawaii, on account of the greater 

 altitude of the islands, is characterised by a special mountain 

 flora, and that it is comparable with Fiji, and to a great extentwith 

 Tahiti, only as regarding the plants of the levels below 1500 metres." 

 In following out the floral history of these islands the author goes 

 back to a time when no Vegetation existed and essays the diflicult 

 task of tracing the epochs of the stocking of the region with plants 

 (Chaps. XX— XXVII). Treub has shown in recent times that the 

 flrst plants to appear in the Island ofKrakatoa after the eruption 

 in 1883, were wind-borne spores of ferns, algae. etc. while later 

 came coast plants, and these distributed by birds. This is regarded 

 as the flrst stage in the stocking of a Pacific Island, and is 

 designated the Age of Ferns. During this period wind-borne spores 

 and seeds arrived and peopled the islands, and, as the ^yind cur- 

 rents have been continuous ever since, the stream of colonists must 

 still continue. Fiji and Tahiti, which are nearest the Indo-Malayan 

 mainland, have still the largest number of ferns and their allies, 

 while the more isolated group of Hawaii has a large proportion of 

 endemic ferns. These endemic species are regarded as having arrived 

 during an early period of the Age of Ferns, and their existence is 

 dependent on the large area of elevated land. The second era is 

 that of flowering plants belonging to genera which are endemic or 

 peculiar to each group of islands, "since it is implied that they 

 have descended from the earliest phanerogams that established thcm- 

 selves in the group". Hawaii again Claims the largest number of 

 endemic genera, and this is connected with its greater isolation. The 

 conspicuousness of genera of Compositae and Lobeliaceae in the 

 Pacific has led the author to designate this as the Age of Compo- 

 sitae. Evidence is given that a certain number of these endemic 

 genera came from America, and that birds were the chief agents 

 of transport. The arrival of these genera is placed during the Tertiary 

 Period when the Fijian area was almost submerged. In this way 

 the absence of many of these endemic genera from the Fijian 

 group is explained. Fiji, however, has its own peculiarities in the 



