176 



and seeds are spread by wind, water and animals was known already 

 long before the eruption. But it was expected that from the investig- 

 ations on Krakatao would appear that and in which manner seeds 

 and fruits are transported across a sea-arm by other means than 

 sea-currents. That expectation has not been fulfilled. Now that the 

 total destruction of the vegetation in 1883 has not been proven and 

 not a single experiment has been made in order to ascertain whether 

 seeds or fruits really were carried across by the wind or by animals, 

 one can only state that the trips to Krakatao have contributed 

 nothing, litterjlly nothing, to the advancement of our real knowledge 

 not our fantasy in this respect. Visitors have found plants, they 

 have assumed that these were imported after the eruption and then 

 they have set themselves to guessing. Light seeds they have had 

 introduced by the wind, fleshy fruits by birds, everything according 

 to the old recipe. But nothing has been proven, none of the so-called 

 results has a scientific base. 



In the last chapter of his paper Ernst traces in bold outlines 

 the development of the flora of Krakatao. 



In 1897 on the beach a Pes-caprae formation was found, in the interior a grass- 

 steppe, on the mountain slopes a fern-vegetation. In 1906 the situation had very much 

 changed. On the beach not only a Pes-caprae-formation but also a (not yet very 

 rich) Borringtonia-iormation occurred; littoral plants were growing to 300 500 m. 

 from the sea; conversely, arms of the grass-steppe which covered the interior projected 

 through gaps in the littoral forest as far as the beach. In the south-eastern l ) angle 

 of the island the littoral vegetation consisted of groups of different ages, the younger 

 of these were found close to the sea, the older ones more towards the interior; this 

 points to the beach having shifted. Considering the composition of the fauna of 

 Krakatao in 1906 it is not probable that seeds of littoral plants were carried by animals 

 to the interior. I he gentle slopes behind the littoral forest and the lower vallies and 

 ridges were in 1906, like in 1897, clothed with grasses, Cyperaceae and Compos/toe; 

 ferns were already in the minority. I rees and shrubs were in 1906 more numerous 

 than in 1886. In stray specimens or in groups they had penetrated from the littoral 

 forest into the interior; in the ravines they had blended into groves. 



If no new eruption takes place, the entire island, except the steep wall formed by 

 the rupture, will be covered after 50 or 60 years with forest. I he littoral groves will 

 blend into each other, new species will appear, others will disappear or retreat to the 

 /Vs-caprae-formation and locally supersede it. A number of the facultative beach 

 plants will be carried to the interior by the wind .or by animals. Possibly the forest in 

 the higher ravines consisted in 1906 already of these littoral plants; subsequent visitors 

 may find there numerous other species brought there by birds and yet more by the 

 wind from other islands, especially from the higher regions of these. The south-east 

 trade-wind can bring many plants from lava. Especially those anemochorous and zoo- 

 chorous species may be expected which in lava and Sumatra form a new flora on 

 volcano-cones deprived by an eruption of their vegetation. As the woods expand and 

 grow denser new conditions arise enabling other plants to live there. The influence of 

 man on Krakatao will be very feeble, the woods will continually extend themselves, 

 the grass-steppe will disappear, but not before many years have elapsed the vegetation 

 will be as rich as that of a tropical primeval forest. 



') By some lapsus calami Ernst wrote south-wesre/v/ angle. 



N 



