310 Professor Bayley Balfour [April 20, 



tdyef rhiho, or watery aloes. In this condition it is exported to 

 Muscat and Arabia, and sells for three dollars the skin of 30 lbs. 

 By keeping, however, the aloes changes in character. After a month 

 the juice gets, by loss of water, denser and more viscid ; it is then 

 known as tdyef gesheesltah, and is more valuable — a skin of 30 lbs. 

 fetching five dollars ; whilst in about fifteen days more — that is, 

 about six weeks after collection — it gets into a tolerably hard solid 

 mass, and is then tdyef kasahul, and is worth seven dollars a skin 

 of 30 lbs. In this last condition it is commonly exported. 



There is, as I have said, no forest on the island, and yet there is 

 one small tree, or large shrub, which may be of some value com- 

 mercially. It is the metayne, a kind of box-tree, Buxus Bildehrandii, 

 It was first found by Hildebrandt on the Somali-land hills. It forms 

 a hard, compact wood, and, I doubt not, might be used for many of 

 the purposes for which boxwood is so valuable at the present time. 

 It is abundant on the island, and Hildebrandt reported it very 

 common in Somali-land. I did not bring home sufficient specimens 

 to allow of an experimental trial of this as a material for woodcuts 

 or other purposes. I learn from Dr. Schweinfurth, that he has sent 

 some to Berlin to be tried in this way. Should the wood prove 

 serviceable, it requires no special mention to indicate how valuable 

 this product may become, in view of the exhaustion of the boxwood 

 forests (of which we hear so much) in the S.E. of Europe. 



Many plants are used on the island for the purposes of dyeing. 

 But of these the only one that need be here referred to is the orchella 

 weed (Boccella tinctoria). Occurring in abundance, it was formerly 

 exported in great quantity. It is known as shennah. 



Surveying the flora from the point of view of its relations and 

 development, we shall consider the Phaenogams alone. The limita- 

 tions of genera and species amongst Cellular Cryptogams — the 

 Thallojohytes in particular — are so uncertain that they afi'ord no basis 

 for comparisons. And I must also state that in making statistical esti- 

 mates of the relations of the flora, one can only do so in the most 

 general way, as our knowledge of the flora itself is not complete, 

 and then we know so very little of that of the adjacent mainlands. 



Of the 600 species and varieties of Phsenogams, which are com- 

 prised in 81 natural orders, and in 324 genera, about 200 are endemic, 

 i. e. endemic species are to non-endemic ones in the proportion of about 

 1 to 3. This proportion is greater than is found in the Seychelles 

 flora, and in that of the Mascarene Islands, but it is less than in the 

 Madagascar flora, wherein Mr. Baker makes the proportion nearly 

 1 to 2. The endemic species and varieties are referable to 143 genera, 

 and of these a proportion to the whole genera of the flora of about 

 1 to 16 is endemic. This is large compared with some other Indian 

 Ocean Islands, but falls far short of Madagascar, where it is 1 to 7. 



The species which are not endemic are almost all referable to 

 genera of considerable dispersion, and of the species themselves we 

 find that about l-4th are cosmopolitan in the Tropics, many of them 



