4 Transactions. 



be roughly proportionate to its area. Now, the Kermadec Islands have 

 a similar area and height to Norfolk Island, and do not differ very much 

 from it in latitude, and consequently they may be expected to contain a 

 similar number of species ; yet for Norfolk Island Maiden gives a list of 

 163 phanerogams and fifty-three ferns (including Lycopods), a total of 216, 

 whereas for the Kermadecs W. R. B. Oliver gives a total of only 115 species, 

 of which thirty-nine are ferns. It would seem, therefore, that either the 

 Norfolk Island list is in excess or the Kermadec list in defect, or that some 

 special cause has been at work to increase the number of species in one case 

 and diminish it in the other. I have little doubt myself that the first of these 

 reasons is the true one. On Lord Howe Island there are also over two 

 hundred species recorded ; but the surface of that island is much more varied 

 than that of Norfolk Island, and it has mountains of upwards of 3,000 ft. 

 upon it. One would, therefore, expect to find fewer species upon Norfolk 

 Island than upon it. 



Tests for Distinguishing Indigenous Species. 



One may feel comparatively sure that the list of Norfolk Island species 

 has been stuffed with aliens ; but when it comes to examining the title of 

 any particular species to appear, difficulties are in most cases encountered. 

 Two questions have to be asked and answered before a decision can be 

 made : (1) Has the plant been found growing on the island ? (2) if growing 

 on the island, is it indigenous or introduced ? 



There are undoubtedly a few plants on the list which have not been 

 found growing on the island. They have been introduced owing to the 

 mixing of specimens in herbaria from different habitats, or to some other 

 form of carelessness, or accident. In dealing with this question I have 

 adopted the following rule : Plants recorded only by botanists who have 

 not visited the island, and without a collector's name, are to be regarded with 

 suspicion. Many of the species introduced into the list by the late Pro- 

 fessor R. Tate come under this category. In deciding whether a plant ha« 

 been found on the island I have also received considerable assistance from 

 the examination of the fine collection in the herbarium at Sydney Gardens. 

 This collection is by no means complete, some undoubted inhabitants not 

 being present in it ; but the absence of a suspected species from this collec- 

 tion adds a further suspicion to the record. I know, of course, from experi- 

 ence how dangerous it is to conclude from negative evidence that a plant 

 has not been found in a given place, and evidence of this character alone 

 should rarely be relied upon. Some of the species found by Bauer do not 

 seem to have been found recently, but they are not, therefore, in any way 

 suspect, as his herbarium is still in existence, and his records are most reliable. 

 Mr. Maiden has endeavoured in his list to cut out doubtful records, but 

 unfortunately does not always indicate those plants which he himself found 

 growing on the island. However, the number of species involved in the 

 doubtful records are few as compared with those which undoubtedly do occur 

 on the island but are doubtfully indigenous. 



I now give briefly those rules which I have followed in determining if 

 a species occurring on the island is to be regarded as a native to it. 



(1.) All plants recorded by Endlicher, with two ot three exceptions, are 

 to be regarded as indigenous. Bauer spent eight months on the island 

 shortly after its settlement, and before the vegetation had been ruined. 

 He was a careful observer, and adds notes in one or two cases where he 

 considers a species doubtfully indigenous. 



