404 APPENDIX E. 



the rocky heights of the interior. The order is not found in 

 the Canary Islands, but reappears in the Cape de Yerdes in a 

 species of Sapota, and is well represented in the humid regions 

 of Western Africa. It would thus appear that Argania and 

 the Madeiran Sideroxylon are two outlying representatives of a 

 very tropical order; and, considering the proximity of the areas 

 they inhabit, and their position in the extreme west of the Old 

 World, they are, in a Botanico-Geographical point of view, plants 

 of a very high interest, as evidences of a relationship between the 

 Floras of these areas, which must originally have been established 

 under very different conditions from those which now prevail. 



The Argan was, as stated above, introduced into England 

 in 1811, and was long estabUshed on a south waU, but tdti- 

 mately was killed in an unusually severe winter. Numerous 

 plants were raised, from seed sent by Sir John Hay, by Mr. 

 Grace, and from those brought by myself, and the plant may 

 be seen in the Economic-plant House at Kew. It is of very 

 slow growth, which has disappointed colonists and others, to 

 whom the fruits have been largely distributed from Kew. 



APPENDIX E. 



On the Canarian Flora as compared with the Maroccan. 

 By Joseph Dalton Hookee. 



In respect of their botanical relationship to neighbouring Con- 

 tinents, Islands or Archipelagos may be roughly classed under 

 two divisions : namely, those which are situated within a mode- 

 rate distance of continents, and whose Floras are manifestly 

 derived from them or have had a common origin with theirs ; 

 and those which are situated very far from any continents, and 

 whose Floras diiier so much either from that of the neighbouring 

 continent or from that of those parts of the continent that are 

 nearest to them, that their origin is a matter of speculation. Of 

 the first division, the British Isles, and probably Vancouver's 

 Island, in North- West America, are conspicuous instances, their 

 Floras being almost identical with those of the neighbouring 

 continents. St. Helena, the Galapagos, Mauritius, and the 

 Sandwich Islands are instances of the opposite extreme, for 

 their Floras differ widely from those of any continents. 



