THE PLANTS OF MAST-HEAD [SEAND. 



By H. A. LONGMAN. 



{Read before the Royal Society of Queensland, June 27th, 1913.) 



Much prominence has been given of late years to the 

 study of island floras, perhaps the most noted instance 

 being that of Krakatan* In 1883, the entire vegetable 

 life there was blotted out of existence by lava streams, 

 the result of a volcanic eruption so gigantic that the sound 

 of it travelled 3,000 miles and was heard here in Queens- 

 land. Yet to-day this island is so thickly clothed with 

 vegetation that in places it is almost impenetrable, and 

 an object lesson has been given of the manner in which 

 organisms re-establish themselves on island homes. The 

 interest taken in the flora of Krakatau is an incentive 

 to Australian botanists to note the growth of vegetable 

 organisms on those islets of our Great Barrier Reef which 

 are known to be of comparatively recent origin. 



The respective theories of elevation and depression, 

 formulated by Murray and Darwin, to account for the 

 growth of coral islands, and somewhat strenuously advocated 

 by adherents of each school, are now found to be both correct. 

 Whilst certain coral atolls are due to depression, others 

 are indubitably formed by elevating influences. The 

 whole of the Barrier Reef region is, of course, the result 

 of subsidence, but varying factors have contributed to- 



*New Flora of Krakatau, A. Ernst ; English trans. A. C. Seward, 

 Cam. Univ. Press, 1908. 



Some doubt has been expressed as to whether the nuts of Coco? 

 imcihra, Linn., the cocoanut palm, ever germinate naturally when cast 

 upon a beach, and in the majority of cases they evidently fail so to do. 

 But in the Flora of Krakatau definite evidence is given that a large number 

 of these valuable palms have established themselves on that island by 

 natural methods. 



