170 



NATURE 



[December 26, 1895 



the foregoing analysis, his attention is mainly concen- 

 trated upon decorative art, the reasoning he has em- 

 ployed must apply to other kinds ; and, indeed, he shows 

 in the course of the volume many instances of such 

 application. The number and interest of the questions 

 he suggests, forbid discussion in the space at my com- 

 mand. The extent of ground covered necessitates deal- 

 ing in a summary manner with certain portions of the 

 field. It cannot be helped. In a work of this kind it is 

 more important to give glimpses of results beyond those 

 actually worked out, than it is to establish a number of 

 conclusions in detail. Prof Haddon is fully alive to 

 this ; and while his conclusions, as far as they go, are in 

 the main sound, and his exposition is clear and forcible, 

 to fulfil the more important office he voluntarily foregoes 

 much that would have added interest in the eyes of 

 specialists, and perhaps in the eyes of others also. For 

 the student every page will have its own suggestions. 

 That humbler, but much more formidable, person, the 

 general reader, for whom the book is also intended, if he 

 be unacquainted with the writings of Holmes, Balfour, Dr. 

 Colley March, and Count Goblet d'Alviella, will find him- 

 self in a new world. He cannot have a more trustworthy 

 and companionable guide, with whom to commence its 

 ^exploration, than Prof. Haddon. 



Most of the figures are well and clearly reproduced ; 

 but a few of them would be greatly improved by the 

 adoption of a larger scale. Some, such as the bamboo- 

 pipes in Fig. I, and Buddha's footprint in Fig. 130, are 

 almost useless, on account of their diminutive size as 

 •compared with the intricacy of their patterns. 



E. Sidney Hartland. 



THE FLORA OF BOURBON. 



Flore de Vile de la Reunion \Bourbon\ . . . avec P Indica- 

 tion des Proprieth Economiques et Industrielles des 

 Plantes. Par E. Jacob de Cordemoy. (Paris : 1895.) 



THE appearance of Dr. Cordemoy's long-promised 

 book on the flora of Bourbon will be welcomed 

 with great satisfaction, as this was the only island of 

 the Mascarene group proper of which the plants had 

 not been worked out in detail. Dr. Cordemoy's work 

 is not compiled on the same lines as the British Colonial 

 Floras, and in some respects compares unfavourably with 

 them ; notably in the want of uniformity in treatment, 

 and the absence of particulars of the general distribution 

 of the plants. But the author has laboured under the 

 great disadvantage of being remote from a botanical 

 centre of literature and collections, and has done ex- 

 ceedingly well considering these drawbacks, except that, 

 with his thirty-five years of experience, he might have 

 given a much more interesting account of the vegetation, 

 and a better summary of the facts brought to light by 

 his investigations. 



Mauritius and Bourbon, separated by about 100 miles, 

 are nearly of the same extent ; but the mountains of 

 the latter rise to an altitude of nearly 9500 feet, or up- 

 wards of 6000 feet higher than those of Mauritius. This 

 additional elevation adds a zone of vegetation to Bourbon 

 which is practically unrepresented in Mauritius ; yet 

 there is no strictly Alpine element in the flora, and the 

 NO. 1365, VOL. 53] 



presence of native species of such genera as Ranttnciihis 

 Stellaria, and Hypericum hardly marks a cold climate . 

 Perhaps the most striking thing in the flora of the two 

 islands is the large number of characteristic genera and 

 species common to both. For example, the indigenous 

 palms of Bourbon are : Hyophorbe indica, Dictyospenna 

 alba, Acanthopha;nix rubra, A. crinita, and Laiania 

 Conimersonii. These are also, all of them, indigenous 

 in Mauritius, and nowhere also. This is a strong con- 

 trast to the strictly endemic palm-vegetation of the 

 Seychelles. On the other hand, Bourbon possesses a 

 bamboo, Nastus borbonicus, which covers extensive areas 

 at 4250 to 6500 feet, growing to a height of 35 to 50 feet. 

 Excluding Pandanus utilis, four species of screw-pine 

 are described ; all endemic, and evidently constituting 

 a prominent feature in the landscape, both on the sea- 

 shore and high up on the mountains. 



Other genera and species common and restricted to 

 the two islands are : Cossignia pinnata (Sapindacese), 

 Grangeria borbonica (Rosaceas), and Psiloxylon mauriti- 

 anum (Lythrarieae ? ). 



Among characteristic genera largely developed in both 

 islands are Dombeya (Malvaceae), Quivisia (MeliaceEe), 

 and the shrubby Psiadia (Compositae). Among moun- 

 tain shrubs of wide distribution within the African 

 region, Phylica nilida and Agauria salicifolia are note- 

 worthy. The former Cordemoy describes as a new 

 species, with the remark that it may be the same as 

 P. viauritiana. I have elsewhere ^ given my reasons, 

 supported by the opinion of previous writers, for uniting 

 the forms of Phylica inhabiting the Tristan da Cunha 

 group, Amsterdam Island, Bourbon, and Mauritius under 

 one species ; and a further examination of the specimens 

 does not alter that conviction. Agauria salicifolia is a 

 common shrub on the mountains of Mauritius, Madagas- 

 car, and Continental Africa, westward to the Cameroons. 



The discovery in Bourbon oi Bryodes micran^ha (Scro- 

 phularineae) is interesting. It is a minute plant, only 

 known at Kew from the one small specimen on which 

 the genus was founded, collected in Mauritius by Bojer. 



Hydnora africana, a root-parasite, found in some 

 districts of South Africa, is recorded as common at 

 Saint Paul, and as being known under the name of Rose 

 de Noel. This is even more remarkable than the dis- 

 covery of a new species of Cytinus in Madagascar. 



As in Mauritius, so in Bourbon, gymnosperms are 

 wholly wanting in the native and naturalised flora ; and 

 at present only one species each of Podocarpus and 

 Cycas is known to inhabit Madagascar. They are both 

 endemic. The phyllodineous Acacia (A. heterophylla), 

 which has lately been recorded as introduced in Mada- 

 gascar, and which is so near the Sandwich Islands 

 A. Koa, as to be hardly distinguishable, if you did not 

 know where your specimens came from, is said to be 

 very common on the mountains, between about 3250 and 

 6500 feet. It is also common in Mauritius, and ap- 

 parently undoubtedly native. 



With regard to the total number of indigenous species 

 of vascular plants, as compared with that of Mauritius, 

 it is not easy to arrive at a satisfactory estimate, because 

 many of the plants now commonest were probably intro- 

 duced ; but 1000 is, perhaps, below the actual number, 



1 " Botany of the Challenger Expedition," i. 2, p. 148. 



