APPENDIX. No. V. 421 



any conclusions concerning the propDrtional numbers of the three primary 

 'iivisions, or of the principal natural orders in the country in which it 

 was tormed. 



Its value in this respect must depend on the relation it may be supposed 

 to have to the whole vegetation of the tract examined, and on the probability 

 of the circumstances under which it was formed, not materially affecting the 

 proportions in question. 



Its probable relation to the complete Flora of the country examined, can at 

 present be judged of only by comparing it with collections from different 

 parts of the same coast of equinoctial Africa. 



1 he first cfm^iderable herbarium from this coast, of which we have any 

 account, is that formed by Adanson, on the banks of the Senegal, during a 

 residence of nearly four years. Adanson himself has not given the extent of 

 his collection, but as he has stated the new species contained in it to be 300,* 

 it may I think, be inferred, that altogether it did not exceed 600, which is 

 hardly equal to that from Congo. Limited as this supposed extent of Adanson's 

 herbarium may appear, it is estimated on the most moderate calculation of 

 the proportion that new species were likely to bear to the whole vegetation 

 of that part of equinoctial Africa, whiili lie was the first botanist to examine; 

 allowance being at the same time made for the disposition, manifested in the 

 accoiuit of his travels, to reduce the plants which he observed to the nearly 

 related species of other countries. 



From the herbarium, and manuscripts in the library of Sir Joseph Banks, it 

 appears, that the species of plants collected by Mr. Smeatlunan at Sierra 

 Leone, during a residence of more than two years, amounted to 450. 



On the same authority I find that the herbarium formed in the neighbour- 

 hood of Cape Coast by Mr, \\' illiam Brass, an intelligent collector, consisted 

 of only v!.")() species. 



And I have some reason to believe, that the most' extensive and valuable 

 collection e\ er brought from the west coast of equinoctial Africa, namely, that 

 formed by Professor Afzelius, during his residence of several years at Sierra 

 Leone, does not exceed li?00 species: although tliat eminent naturalist, in 

 the course of his researches, must have examined a much greater extent of 

 eountry than was seen in the expedition to Congo. 



From these, which are the only facts I have been able to meet with respecting 



* Fam. des Plant. I. p. exvi. 



