480 APPENDIX. No. V. 



natives of Egj-pt ; Glinus lotoides of Egypt and Barbary ; and Flagellai-ia in- 

 dica, existing on the east coast of New Holland, in as high a latitude as 32°. S. 



4th. It may perhaps be suggested with respect to tliese lists, that they contain 

 or even chiefly consist of plants that during the constant intercourse which has 

 now subsisted for upwards of three centuries between Africa, America, and 

 India, may have, either from design or accidentally, been carried from one of 

 these regions to another, and therefore are to be regarded as truly natives of 

 tliat continent only from which they originally proceeded. 



It appeai-s to me, however, that there is no plant included in any of the lists 

 which can well be supposed to have been purposely carried from one continent to 

 another, unless perhaps Chrysobalanus Icaco, and Cassia occidentalis ; both of 

 which may possibly have been introduced into America by the Negroes, from 

 the west coast of Africa ; the former as an eatable fruit, the latter a<i an article 

 of medicine. It seems at least more likely that they should have travelled 

 in this than in the opposite direction. But I confess the mode of introduction 

 now stated, does not appear to me very probable, even with respect to these 

 two plants ; both of them being very general in Africa, as well as in America ; 

 though Chrysobalanus Icaco is considered of but little value as a fruit in either 

 continent ; and for Cassia occidentalis, which exists also in India, another 

 mode of conveyance must likewise be sought. 



Several species in the lists, however, may be supposed to have been arci- 

 dcntnUy carried, from adliering to, or being mixed with, articles of food or 

 commerce ; either from the nature of the surface of their pericarpial covering, 

 as Desmochfeta lappacea, Lavenia erecta, Ageratum conyzoides, Grangea ma- 

 deraspatana, Boerhaavia mutabilis, and Hyptis obtusifoha ; or from the minute- 

 ness of their seeds, as Schwenckia americana, Scoparia dulcis, Jussisea erecta, 

 and Sphenoclea zeylanica. That the plants here enumerated have actually been 

 carried in the manner now stated is, however, entirely conjectural, and the 

 supposition is by no means necessary : several of them, as Lavenia erecta, 

 Scoparia dulcis, and Boerhaavia mutabilis, being also natives of tlie intratro- 

 pical part of New Holland ; their transportation to or from which cannot be 

 supposed to have been effected in any of the wavs suggested. 



The probability, however, of these modes of transportation, with respect to 

 the plants referred to, and others of similar structure, being even admitted, 

 the greater part of the lists would still remain ; and to account for the di.sper- 



