The Problems of Plant Distribution 265 



and by that time a good many plants had already 

 established themselves. Apparently the earliest 

 plants to get a foothold were blue-green algae, which 

 were found growing on the barren cinders, forming 

 black gelatinous films in which fern spores were able 

 to germinate, so that nearly a dozen species of ferns 

 were noted on this first visit. 



With the rapid decay of the dead vegetation, and 

 the decomposition of the ashes under the sun and 

 rain of an equatorial climate, soil enough was soon 

 created for the maintenance of many flowering 

 plants, whose seeds, borne by the wind, or by birds, 

 or carried by the ocean currents to the shore, quickly 

 spread over the bare surface of the island. 



I had an opportunity of visiting Krakatau in 

 April, 1906, twenty-three years after the eruption. 

 At this time the island was completely covered again 

 with vegetation comprising a large number of species 

 of flowering plants. Along the shore, the character- 

 istic strand flora was completely reestablished. 

 Fruiting cocoanut palms, Casuarinas, screw-pines, 

 and various other trees, some of them fifty feet in 

 height, formed a belt of forest, with lower vegeta- 

 tion growing immediately along the beach. The flat 

 land between the shore and the remains of the cone 

 in the center of the island, was covered with a dense 

 growth of tall grasses, with a sparse growth of 

 shrubs and other plants between. In the more shel- 

 tered hollows about the base of the cone, a dense 

 growth of young forest trees had established itself, 



