Books and Current Literature. 45 



A highly interesting account of the new flora of Krakatau 

 is given by Professoi D. H. Campbell in the American NaturaliH 

 for August, 1909. The extraordinary volcanic eruption which 

 occurred in the Straits of Sunda in August, 1883, resulted in the 

 total obliteration of the luxuriant vegetation of Krakatau, even 

 the dense forest which extended to the summit of the highest 

 peak being completely covered by a deep mass of hot ashes and 

 pumice. Since the whole island was thus efficiently sterilized, 

 and was comparatively isolated, a unique opportunity was pre- 

 sented for studying the re-establishment of vegetation on an 

 extended and absolutely barren area. 



The first botanical expedition for this purpose was made in 

 1886 under the direction of Professor Treub, so long in charge of 

 the botanical gardens at Buitenzorg, Java It was found that 

 duiing the interval of three years which had elapsed since the 

 eruption, a considerable number of plants had already estab- 

 lished themselves upon the island. Conspicuous among flower- 

 less plants were the blue-gieen algae, the slimy films of which, 

 coating the surface of the ashes, formed a favorable substratum 

 for the germination of spores and the seeds of a few phanerogams. 

 The prepondeiance of ferns in the new flora was particularly 

 marked, no less than eleven species being found. Fifteen 

 species of phanerogams had established themselves, but they 

 weie fai less numerous in individuals than the ferns. 



A second expedition, also undei Treub's direction, was made 

 to the island in 1897. During the interval of something over 

 ten years since the first visit, the number of plants had greatly 

 increased and characteristic associations had already begun to 

 be foimed. The total number of vascular plants amounted to 

 sixty-two, of which twelve were pteridophytes and fifty phaner- 

 ogams. 



A third paity visited the island in 1905, and in the spring of 

 1906 a visit was made to it by Professor Campbell, Professor A. 

 Ernst of the University of Zurich, and several others. For 

 these various expeditions the results so far published give a total 

 of 137 species established on the isb.nd, of which a very large 



