too few; and, accordingly, I fear the greatest defects are on this side. All the maritime plants of course come under the denomination of rare, in consequence of their almost total absence from the inland counties.

The same occurs with some confused, doubtful, or misnamed species, though really found to be common when sought for. We have examples in Tragopogon major (identical with T. pratensis of British authors,) Veronica polita (confused with V. agrestis, and almost equally common,) Enanthe apiifolia (identical with E. crocata,) and several willows and brambles. These are omitted in the Supplement. Callitriche pedunculata, Habenaria chlorantha, Carduus crispus, and others, are probably common, though overlooked, or not distinguished from nearly allied species or varieties.

It is also to be remembered, that a work of this kind is a compilation, chiefly composed of what has been said by others about the localities of plants; and that it must unavoidably include, in many instances, not only what still is, but also what has been, and even what has been only supposed to be. A copious source of error is implied in the last words in italics, and one that it is impossible wholly to keep clear from. I do not hold myself accountable for the mistakes of others, and the frequent use of the sign of doubt (?) will indicate that many errors have been presumed. Were my own share of the volumes clear of defects, I might feel surprised at the mistakes of others; but, unfortunately, this is by no means the case, although comparatively with the quantity of unconnected details, the errors of serious import are few. In transcribing from the manuscript notes of others, sometimes neither methodically arranged nor written in very legible characters, I have occasionally mistaken words, particularly proper names which have not been familiar. Again, when there are several places

of the same name, unless an author or correspondent specifies which of such places is intended by him, there is great chance of error arising from misposition, and the consequent creation, (so to express it,) of a false station. Perhaps one half the places in Britain have names in common to at least two of them, and several names apply to as many dozens or scores of places. This circumstance has caused me, as well as other botanical writers, to misplace some habitats or stations; but about half a dozen of similar errors are so remarkable as to call for an explanation. They arose from writing down the localities, as procured, on separate slips of paper; and in afterwards arranging some thousands of these slips of paper, according to counties, a few clung together, or got misplaced by some other means, and six or eight were even printed without the false position being noted by myself until too late. The necessary corrections are made in the Supplement. Of course, this does not invalidate the stations, which will be correct in themselves, although copied on a wrong page of this work. It will also be observed that the same locality is occasionally given twice over, as taken from different authorities. This is done chiefly with the rarest species, where the two descriptions form a better guide in connexion, or mutually confirm each other. The object is usually so evident that I should not have deemed any explanation called for, had not four botanists severally told me that the different descriptions of the station for Cyperus fuscus (Page 102) were intended for one single place. In this instance, I was aware of the fact, but sometimes considerable doubt might be felt, and then the two descriptions would both be given. The plan of citing the specimens preserved in my Herbarium has also induced some repetition. Independently of the smaller defects arising from errors of the pen or the press, a compilation like the

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present unavoidably contains errors of a more weighty kind, depending less upon the editor than upon others. In a science where so many individual objects and petty details have to be considered, none of its votaries, be they learners or learned, can avoid occasional inadvertencies; and in recording the localities of plants, there is the double chance of error, arising from a mistake either as to the plant itself or as to the place where it has been found. Few-perhaps none of our later botanists who have written a Flora, or published any extended list of stations, have wholly avoided such errors; and the farther we go back in date, the greater was the liability thereto. If once printed in a work of any authority, these inaccuracies are perpetuated by succeeding writers who copy them, and the mass of error goes on accumulating. The customary mode of continuing to repeat the first authority for a station, even one of a century or two in standing, must greatly tend to keep up these blemishes in botanical books. It is on such account that I have been induced to depart from the routine, and always to give the preference to a modern work or living botanist, especially the latter. If there is already another authority in print, the second becomes a confirmation; and in increasing our evidence of the fact in question, it becomes better worth printing than a literal repetition of what has been already made public. But in default of better or more recent authority, a large number of stations have been introduced into these volumes really on old or very doubtful authority; a much greater number than should enter them had they now to be reprinted. Increased familiarity with the subject has led to the persuasion, that it is far better to lose some good facts, than to receive them when largely mingled with erroneous statements. In the first volume, regret was more than once expressed, that the circumstance of writing in the country, out of convenient

reach of libraries of reference, had prevented the search through county histories, guide books, and other nonbotanical works, for the localities of plants occasionally recorded in such publications. I must now, however, retract such expressions, and intimate an opinion that it is just as well to neglect non-botanical works, unless when the lists of plants contained in them have been drawn up by competent botanists, and from actual observation.

A friend remarked that there was something rather egotistical "in appearance, if not in reality," in the particular reference to specimens in my own herbarium. This may be so; yet the plan seemed desirable, because the "sp." following the name of a person does not intend only that he had sent a specimen, but implies that a specimen in proof of the station is preserved in my Herbarium, and can be inspected in case of doubt. It will be observed that a large number of the localities recorded in these volumes are now confirmed by this visible testimony, which, on the death of the present possessor, can be given to some botanical or scientific society, as being an useful record and proof for our successors. Besides, were it merely a matter of entire indifference, those friends deserve a preference who have taken the trouble to procure and send the specimens; and much rather should it be given to them, when the correctness of the alleged facts thus becomes more surely certified.

It has been suggested that county lists relate to an inconvenient extent of surface, and that subdivisions into parishes, or even areas of smaller extent, would be preferable. This seems plausible; and could the suggestion be carried into effect, a work so constructed would prove extremely useful. Unfortunately, many difficulties would have to be encountered. For example, numerous indications of localities are made either to counties simply, or to the vicinities of particular towns or villages, so that a

stranger (and one writing a Guide to Britain in general must be a stranger to a large portion of the country) cannot possibly tell in how many, or in which parishes, the plant in question is to be met with. Fully the half of our published localities would be found unavailable in any attempt to make a Guide on this plan. Supposing the loss of these general indications to be compensated by a large accession of accurately noted stations from new or renewed observation, a second very weighty objection arises, and one that would become more serious in proportion as the first mentioned difficulty was lessened. I allude to the great increase of bulk and cost, which would unavoidably attend such an increased number of local lists. We may find an instance of this in a book published since the first volume of the present work was issued, namely, Mr. Cooper's Flora Metropolitana, mentioned on page 586. It is really a Botanist's Guide, almost on the plan under consideration, and having no claim to be entitled a Flora. This work relates to an area about equal in extent to a single county of average size; lists of some of the plants, at a hundred and fifty different places within the area, being given. The price of the Flora Metropolitana is 4s. 6d., and it cannot be called an overcharged book. The average cost of a county list, in the first volume of the present work, is below 24d.; the list for Yorkshire, the largest of them, being only 8d. If the stations of the Flora Metropolitana had been printed in the same form, they would not have filled so many pages as this Yorkshire list, and therefore might have cost fewer pence. I do not make such comparisons with any wish to depreciate the work of Mr. Cooper, which I regard as a useful addition to the botanist's library, but solely with the view of shewing that the same kind of facts are here conveyed in a much cheaper and more. portable form,-advantages which it is worth while to.