APPENDIX TO THE 'SPICILEGIA GORGONEA.' 309 
lected and in part irretrievably spoilt after their arrival in France. 
Nevertheless this collection still includes a few undescribed species 
and many new to the Flora. In several instances they are identically 
the same as those met with by former travellers, but of these species 
added to our Flora, a much greater number in proportion are either 
natives of the intertropical regions of Western Afriea, or belong to 
analogous orders and genera, and fewer of them than of those found 
by the British collectors appertain to the Flora of the Macaronesian 
region. 
The Canaries may be considered as the centres of this kingdom 
of Flora, which, extending northward as far as the Azores, occupies 
isolated points from the 15th to the 40th degree of northern latitude, 
the equability of an oceanic climate compensating for the distance. 
It is true that a similar vegetation is not found along the whole of this 
line in similar stations. Thus the Canarian forms which occur in the 
Cape de Verd Islands, as Huphorbia Tuckeyana, Steud., Campylanthus 
Benthami, Webb, Sonchus Daltoni, Webb, and others, which replace 
analogous species of Teneriffe, appear, not on the coast, but on the 
mountains of the Gorgonean group. A Senegambian vegetation 
occupies the coast; the same law operating which causes the plants 
of the coast-line in the arctic regions to reappear on the summit of the 
Alps, and Rosa canina, Pyrus Aria, and other European species to 
occupy a station 9,000 feet above the level of the sea and the Peak 
of Teneriffe. 
Nearly a fifth of the species enumerated in the ‘ Spicilegia Gorgonea ' 
belonged to the Macaronesian region,—a remarkable fact, since the 
Cape de Verd Islands are on its extreme southern frontier. This 
proportion will be now slightly diminished. In the south this Flora 
is combined with tropical, in the north with Mediterranean and 
Arabian forms. The central or Canarian group, the richest in indi- 
genous vegetation, as described in the Phytographia Canariensis, 
contains, out of 1,116 species of flowering plants and ferns, 363 
(or about a third) peculiar to the region of which it is the nucleus. 
The Azorian group is not yet thoroughly investigated; but it is 
probable that, being nearly as far removed from the centre in a northern 
direction as the Cape de Verds are towards the south, the proportion 
of their Flora appertaining to that of the central cluster of islands 
will not be very different from that of the tropical group,—that is to 
say, less than a fifth. 
