of certain British Plants, 85 



history of the indigenous vegetation of our country. We 

 ought, at least, to be agreed about rejecting some species which 

 have erroneously crept into our flora, and we ought to en- 

 deavour to agree about others which have certainly been 

 introduced by the agency of man. But, besides these, I 

 think we might notice a third class, concerning which I am 

 more particularly desirous of obtaining the opinions of your 

 correspondents and others ; to be composed of species, of 

 whose introduction we cannot feel positive that it should be 

 attributed to the agency of man, but of which we have a 

 " suspicion " that they were thus introduced, arising from the 

 peculiar conditions under which they are found. We might 

 indicate this suspicion by some mark, as (f ), distinct from that 

 (*) by which we characterise the certainly naturalised species. 

 If these dubious marks were to accumulate against the same 

 plant obtained from various stations, we might hunt it, as it 

 were, back to the spot from which it had originally roamed 

 in the society of man to other botanical regions, but in which 

 it would not have been found, had it been left to the operation 

 of natural means alone for its dispersion. The considerations 

 upon which I conceive these marks of doubt may be made to 

 depend, I shall presently revert to. 



The idea of soliciting discussion on these points has prin- 

 cipally originated in a wish to promote an enquiry which has 

 been ably commenced by Mr. Watson, respecting the geo- 

 graphic distribution of the plants of Great Britain. [See VI. 

 265. and VII. 20.] This gentleman has rejected many 

 species commonly admitted into our flora, and has increased 

 the list of naturalised species, by including several of those 

 which are usually considered to be strictly indigenous, and 

 has also grouped together, as varieties, several plants which 

 are generally accounted distinct species. These are all points 

 in which our flora stands in need of a decided reformation; 

 and, so far as my own observations have enabled me to judge, 

 I generally agree with Mr. Watson's proposed emendations. 

 We may, possibly, arrive at farther results by a more general 

 discussion of these points, and I know of no place so well 

 adapted to this purpose as the pages of your magazine. I 

 have engaged several of my botanical friends in the University, 

 who are in the habit of meeting once a week for conversing 

 on subjects connected with natural history, to discuss the 

 circumstances under which they may severally have noticed 

 the species included in our flora, so that the communications 

 which I may hereafter transmit to you must be considered as 

 the joint-stock opinions of our resident botanists. There are 

 four heads to which our enquiry will extend : — 



g 3 



