PREFACE.

DURING the interval of nearly a year and a half since the publication of the first volume of the New Botanist's Guide, many additions and some corrections have been obtained, which are added as a Supplement in the second volume. While the published portion of the work has been thus improved, comparatively little advantage has accrued to the Scottish portion, forming the first part of the second volume; so few additions having been made to it, that it appears now almost the same as it might have done a year or two ago. This circumstance affords us a good illustration of the usefulness of collecting into a small focus the chief part of what is already known in regard to the localities of plants. Every botanist is able to add something to the general stock of knowledge, and many are desirous to do so; but few of them can know what is most worth communicating, on the score of novelty or otherwise, until some one has taken the trouble of drawing together the detached facts and fragments into groups sufficiently methodical for reference. The Editor of these volumes would certainly have preferred to see some other individual take up the task; but not finding any one disposed to do so, amongst those to whom the suggestion was made, and feeling much the want of such a book for his own use, he at

length resolved to set about it as a private MS. Publication was ultimately decided on, as the best means of advancing this department of botany, in which the cooperation of many persons is so necessary for success. Even with the assistance which has been freely given by others, in communicating details of stations, the editorial labour has been very far from slight; and it is unavoidably of that dull plodding kind which is apt to be felt as a tedious task rather than a pleasurable occupation. He has, nevertheless, been somewhat encouraged and cheered in his labours, by the conviction that the work will afford assistance in investigations which may ultimately prove of very high importance, although such a result may not be apparent in our own day.

Several criticisms and suggestions having been offered by botanical friends, it is wished to make some explanations in reply to their comments, partly in farther explanation of the work, and partly as hints for any future writer on the same subject. It was explained, in the Introduction to the first volume, that two objects were kept in view in preparing the work. Of these, an endeavour to ascertain the mere distribution (or areas) of the species, by making a series of local lists from such data as were within reach, was the first and most desired The other use of the compilation, as a guide-book to the localities, was a second and secondary object, easily combined with the former, and lending considerable assistance to it. Several of my friends have regarded the work solely in this latter view, and thus have been unable to conceive wherefore the names of plants should be repeated in the lists for counties in which they are abundantly common; and also, why such vague localities as "Somerset," 'Bristol," "Norfolk," &c. &c., should be mentioned. Though useless indications to mere collectors, such notices were intended to record the fact of the plants

one.

being found in the county or vicinity mentioned, a fact which will be useful to any one investigating the distribution of the species. And since the work was designed to shew both the localities and areas of all species entitled to be called rare, with reference to Britain in general, it became necessary to mention them in all the counties within which I had ascertained them to grow, although they might be common in some particular county.

The name of Botanist's Guide was taken as a familiar and explanatory title, and as an admission of the general plan of the work being borrowed from Turner and Dillwyn's Guide. Indeed, it was on expressing a wish that a new edition of their Guide should be published, that the undertaking of a similar work was first suggested to me, although not then assented to. Yet the addition of "New" to the name of the work ought to have indicated that it was not designed to be simply a second edition of that published by Turner and Dillwyn; while the numerous additions, with some changes of plan, it is conceived, must fully make good my right to call it a different work. The list of contributors, and of works from which localities have been copied, pages 669–674., will shew at a glance how large a portion of the contents have been derived from other sources. Almost without exception, the whole of the second volume is additional, and in the first volume, fully three-fourths of the references are made to other works or authors. Again, Turner and Dillwyn seem to have had no settled plan or test as to which species were to be admitted, and which were to be excluded from their county lists. The selection of a certain set of species according to some fixed test, even though it may not be altogether unobjectionable, and then tracing them through the whole of Britain, appears to be a decided improvement, as making the negative evidence available to the botanical geographer. Another

great difference is found in the exclusion of cryptogamic plants. To a few persons this will appear a defect; but if we bear in mind that scarcely one in six of our botanical collectors feel equally interested in cryptogamic plants as they do in the other kinds, unless it be for the ferns, the consequence of including the cryptogamic orders would have been felt in a great increase of price to the consumer, without due equivalent, or a great additional loss to the producer. In Turner and Dillwyn's Guide, the cryptogamic plants average nearly one in three, in the county lists, which must have added to the cost of their volumes in nearly the same proportion. In the present work, the omission of these plants, the small type, and the closer lines have enabled me to give probably six times the number of localities for the phanerogamic plants, in the same number of pages. The defect or omission can be remedied by any one who is anxious to have it done, and is willing to give so much time and trouble to it. I should be glad to see such a continuation of this Guide.

With regard to the line of distinction between rare and common plants.- No better test than the one adopted, has been suggested to me; and, indeed, no objection has been offered to the plan or principle followed. But some few friends have favoured me with remarks to the effect that certain species,-Habenaria viridis and Pinguicula vulgaris, for example, have been excluded, which are as well entitled to be called rare, as are others which have been admitted, — examples of which occur in Clematis Vitalba and Tamus communis. Amongst other species, these have been instanced; and a northern botanist will readily guess that such examples must have been given by one chiefly familiar with the plants of the southern half of England; the two latter not being indigenous in Scotland, where the two former are plentiful, although frequent

enough in the south of England, where the others are rarities. Similar local differences will usually explain and answer the objections; nevertheless there is some ground for them. Between the least rare of the rarer plants, and the least common of the commoner plants, there can be only a shade of difference, and any adopted test will fail of extreme precision; but in cases where the rarity or commonness of a plant is thus in suspense, as it were, it becomes of small moment whether we admit it or reject it. The test adopted, that of the comparative frequency in the local Floras, is a substitution of the average observation of several good observers in different places, for the partial observation of the individual; which latter is really the sole test when any one person takes the result of his own observations or memory as the criterion. The local catalogues as yet published are not sufficient for complete precision, but as they keep increasing in number the test will become more exact; if, indeed, the present work does not now afford a better one, for all the plants enumerated in it. Of the excluded ones, perhaps, there are only two species which ought to have been admitted, namely, Inula Helenium and Potamogeton heterophyllus; the former rejected as occurring in ten out of twelve Floras used for the comparisons, and the latter having been accidentally omitted in transcribing the list of rarer plants, although falling within the prescribed limits of rarity. Some few other species might have been introduced without any impropriety, although there may not be much call for their admission; such, for instance, as Epilobium angustifolium, Arabis hirsuta, Cerastium aquaticum, and Avena pubescens; the last of which has been introduced into the Scottish lists, though inadvertently. But a test

which excludes little above one-third of the whole number of British plants is more likely to admit too many than