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Jnines Small. 
sure that seeds must be carried to great distances as if vve had 
seen them so carried,” and he furnishes a very good argument 
against the negative observations of De Candolle (who relied 
chiefly on the statements of the sailors that they had seen insects 
hut not seeds blown long distances out to sea), and Kernel’ (who 
examined some part of the surface of a glacier but found no seeds 
other than local species). Wallace points out that if “ every year a 
million seeds were brought by the wind to the British Isles from 
the continent, this would he only ten to a square mile, and the 
observation of a life-time might never detect one; yet a hundredth 
part of this number would serve in a few centuries to stock an 
island like Britain with a great variety of continental plants.” He 
also notes that the arrival of seeds and colonisation are different 
matters; seeds arriving on ground already fully occupied would 
require more than a wind-dispersal mechanism to enable them to 
compete successfully with the established inhabitants. 
Beccari (2) gives evidence for the dispersal of seeds for 
distances of 1000-2000 miles, e.g., Nepenthes ampulluria from 
Ceylon to the Seychelles, but does not mention any special 
Compositae. Similarly Engler (14) gives fourteen species of 
Angiosperms as transported by wind to the Sandwich Islands, 
but excludes the Compositae on account of the width of sea to 
be crossed. Warming (42) also supports wind-dispersal to a 
distance of at least sixteen miles for quite heavy fruits. The 
distance is increased by Vogler’s observations (38-40), but this 
author points out that, although wind-dispersal of seeds is possible 
up to 100 kilometres, more importance is to be attached to such 
dispersal for 3-20 kilometres and to the possibility of dispersal 
over high mountain ranges. Kronfeld (26) considers the rapid 
dispersal of various introduced Composites to be due to the 
efficiency of the pappus. Ridley (31) also considers that plumed 
fruits “ can at least occasionally cross successfully large areas 
of sea,” but points out that dense forests present an obstacle to 
the free dispersal of pappose fruits. Further confirmation of the 
efficiency of the pappus is given by Bessey (6). Schimper (32, 
p. 80), after giving the views of De Candolle and Kerner, quotes 
the case of Krakatau as evidence of wind-dispersal for twenty miles 
over the sea, and considers that “ the significance of anemophilous 
means of dispersal in relation to the origin of an insular flora has 
been finally determined by Treub’s important observations.” 
The case of Krakatau is of special, interest since of the eight 
