THE VEGETATION OF THE JUAN FERNANDEZ ISLANDS 8oi 



account. Attention was also paid to the ecological factors, and the reasons set 

 forth why the flora should not be called subtropical, as Johow did, but warm 

 tem[)erate. Special attention was given to bud protection. Schimper's theory 

 on the biological significance of the rosette-tree life-form was discussed and re- 

 futed. 



After our return from the expedition of 1916 — 17, a number of preliminary 

 reports were published [4 — 7), and in 1920 the botanical volume of the present 

 work began to appear in parts. With regard to purely taxonomical papers I 

 refer to the Bibliography. An additional general report of the expedition and 

 its results appeared in 1924 [16). A number of small papers on the ecology and 

 sociology of the vegetation were published from time to time, and some of them 

 are briefly summarized here. In 1925 (//) I gave an account of the Alpine flora 

 of Masafuera, its relations, growth forms and geographical elements. In a paper 

 read before the Ithaca botanical congress in 1926 [ij] I expressed my opinion 

 that some means ought to be found to make an , analysis of exotic vegetation 

 more intelligible to a reader not at all familiar with the flora. I suggested using 

 a system of wellknown habit-forms with which the species mentioned in describing 

 the composition of a community could be compared. The method was illustrated 

 by the principal communities of Juan Fernandez; all the vascular plants were 

 referred to a habit type represented by some wellknown life-form or genus, with 

 the leaf size added according to Raunkiaer. I don't suppose that anybody paid 

 much attention to this proposal, and I shall not use this method here, because 

 most of the species are illustrated. An abstract of a lecture on the plant com- 

 munities has also been published [16) and, finally, a condensed account dealing 

 with the same subject {20). On Masatierra we made a detailed survey of the 

 sociations of Bryophytes found in the old convict caves, with special regard to 

 the light conditions {17). 



I shall conclude this summary by calling attention to recent publications by 

 other authors. E. L. Branchi gave a popular account of the geography with 

 an appendix on the vegetation, entirely based on the writings of Johow and Mo- 

 seley. G. Looser reported on his two visits to Masatierra, and gave a general 

 account of the plant life. He made the rather unpleasant discovery of Riibus 

 ulmifolius Schott, a most unwelcome new arrival: "Esta es la linica novedad que 

 he descubierto en Juan Fernandez . . . debe haber llegado en los ultimos 10 

 anos . . . Es poco abundante, pero mucho temo llegue a ser un enemigo terrible 

 para la flora indigena" (p. 391). Some time ago Mr. Looser told me that this 

 serious pest was reported to have increased very fast. Unfortunately, the fruit 

 is edible. Finally, Miss FiLOMENA Ramirez condemned the illegal traffic in palm- 

 wood, living treeferns etc. which threatens the native forests with destruction. 



