146 HEREDITY AND EVOLUTION IN PLANTS 



wind is known to be a factor in plant-distribution in the 

 West Indies. Thus, for example, previous to 1899, the 

 sedge, Fimhristylis spathacea Roth, was not known on 

 Great Bahama island, of the West Indies. After the hur- 

 ricane of August 13, 1899 this sedge appeared in clearings, 

 and "soon spread as a troublesome weed through culti- 

 vated lands, killing out pasture grass in places; it had 

 therefore come to be called 'Hurricane Grass. "^ 



In August, 1883, the island of Krakatoa, west of Java 

 in the Sunda Strait, experienced a terrific volcanic erup- 

 tion, which completely destroyed every vestage of its 

 vegetation, converting the green island into a desolate 

 desert. Within three years thereafter Treub found grow- 

 ing there six algae and 26 vascular plants, including 11 

 ferns and 15 spermatophytes. A little over ten years 

 after Treub's visit Penzig found 62 vascular plants, of 

 which 60 per cent, had been brought by ocean currents, 

 32 per cent, by wind, and 7 per cent, by fruit-eating birds. 

 Within twenty-five years from this eruption the island was 

 again green with forest growth and other vegetation, and 

 in 1906 a party of botanists confined their collecting to a 

 narrow zone of forest near the shore because of the diffi- 

 culty of "cutting a way through the dense growth of tall 

 grasses" between the shore and the volcanic cone in the 

 center of the island. Among the means of transportation 

 of plant life to Krakatoa, the wind is regarded by Ernst as 

 a factor of exceptional importance. Up to 1906, as cal- 

 culated by him, 39-72 per cent, of the total number of 

 phanerogams on the Krakatoa group were brought by ocean 

 currents. Tento i9percent.of theentireflorabybirds,and 

 16-30 per cent, by air-currents. Beccari found the same 



iBritton & Millspaugh. Bahama Flora., p. 51. Unpublished. 



