152 HEREDITY AND EVOLUTION IN PLANTS 



returning the following spring to the Arctic coast, but 

 by an entirely different rout, passing over Central America, 

 the Gulf of Mexico, and across central North America. 



The Pacific golden plover nests along the arctic shore 

 of Eastern Siberia and the western coast of Alaska, 

 but winters in southeastern Asia, eastern Australia 

 and generally in the islands of Oceanica, the winter home 

 having an east-west range of about 10,000 miles. The 

 journey from Alaska to Hawaii, a distance of some 3,000 

 miles, is made in a single flight. 1 Whether seed dispersal 

 is actually accomplished by any of the above long distance 

 travelers is not definitely known to the writer; but the 

 flights are accomplished in a comparatively brief period, 

 and it seems not unreasonable, from what we actually 

 know of seed-transportation by birds, that lighter and 

 more resistant seeds and spores of plants may be thus, 

 transported, concealed in the plumage of the birds, or 

 otherwise, and between stations where no other known 

 agent of dispersal would appear to be adequate. 



In 1911 a violent eruption of the Taal Volcano, on 

 Volcano Island, Luzon, Philippine Islands, "annihilated" 

 (as Maso described it) every vestage of vegetation on the 

 island. The destruction was caused by superheated 

 steam, and by the deposit of a layer of fine "mud," 

 which fell like rain, and carried with it large quantities 

 of sulphur dioxide and possibly other substances fatal 

 to plant life. In a study of the revegetation of the island, 

 made six years after the eruption, Brown, Merrill, and 

 Yates found evidence that birds were the most important 



1 For the above data on bird migrations the author is indebted to the 

 article on "Our greatest travelers," by Wells W. Cooke. Nat. Geographic 

 Mag. 22 : 346-365- April, 1911. k 



