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by water-sheds. In the nine chapters which follow, the physical features of these divisions appear to be well described; special prominence being given to details of plant topography which illustrate these features. To each chapter, (and a chapter is devoted to each drainage district) a geographical analysis of the district Flora diseussed is appended. The species are grouped under seven sets, viz, Montane, Xerophilous (affecting dry situations), Maritime, Hygrophilous (growing in water), general ascending (occurring in all the nine districts), scattered ascending (in fewer than nine but not less than four of the districts), and local ascending (in from one to three of the districts) species.

The number of native species in each category we copy from Mr. Baker's table.

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Twelve species are entered both as montane and xerophilous; the total number of native species being 872.

Comparison of analyses similar to the above, given for each district, with the physical features of the same, is very suggestive, but time and space forbid our entering upon it here. Mr. Baker points out, that when the number of species in any one of his seven categories is predominant in a District, there also the number of individuals of such species grow in relatively greater abundance than in districts in which the number of species of the same category is smaller. In illustration, he states the number of montane species in his West Tees District to be 77, in East Swale District 23. The relative number of individuals of these montane species, he is assured, is represented more nearly by the squares of these numbers, viz. as 5929: 729 (not 529 as given by Mr. B.), than by their unmultiplied proportion.

Part III. is specially devoted to the Botany of the North Riding, the enumeration of species being prefaced by a short introductory chapter touching upon (1) the specific term, (2) the influence of human agency in modifying a Flora, (3) the stational range of species, (4) the influence of temperature, and (5) of humidity upon the distribution of species, and (6) an explanation of the author's method of stating the distribution of the species included in his enumeration.

The observations upon the influence of temperature, include some sensible remarks upon the proposal of M. A. De Candolle to formulize the sums of temperature necessary to the complete development of different species.

In the list of species, the author has taken the "London Catalogue" as his standard of nomenclature and arrangement. The facility which this reference to a common standard affords to workers who may have occasion to institute comparisons between different Floras, greatly outweighs any objection which can reasonably be made to the employment of the "London Catalogue" for such purposes by British botanists, and it has the further advantage of being in conformity with the standard work upon plant distribution in Britain, Mr. Watson's " Cybele Britannica."

We have no remark to offer with reference to Mr. Baker's valuable enumeration, which occupies nearly all the rest of the book, -about 146 pages. We have already indicated the kind of information which it embraces. Mr. Baker, we observe, includes the Mistletoe, as does Mr. Babington, in Corolliflorae.

We cannot dismiss our notice of this work, without expressing our approval of its thorough and satisfactory character. It contains a great deal of important and valuable original matter, which has been accumulated with much pains.

Before going to press with another edition, we would suggest to the author, the propriety of revising the construction of some of his sentences, which, although they may be strictly grammatical, are somewhat involved, and require to be read two or three times before their meaning can be fully understood. The punctuation is especially faulty, and to this may be due, in part, the ground of our little complaint. It is due to the many excellencies of the book to point these faults out, especially as a reprint will probably be called for.

The title-page of Mr. Brewer's "Flora of Surrey" is rather a long one, having to explain that the work is based upon material collected by the late Mr. Salmon of Godalming. The book consists of (1.) an Introduction, devoted to brief sketches of the Physical Geography and Botanical Divisions of the County, with a note on the general plan of the work; (2.) the Flora, the arrangement and nomenclature of which are in conformity with the London Catalogue; (3.) Appendix A.-Plants probably introduced and not thoroughly

naturalized; (4.) App. B.-Plants found by the Thames near Wandsworth and Battersea, undoubtedly introduced; (5.) App. C. -a table showing the distribution of species upon the different geological formations; and (6.) App. D.-Tabulated numerical proportions of the species of each Natural Order to the entire Flora of Surrey, and to the Flora of the United Kingdom.

The Botanical divisions are adopted "in accordance with Mr. Salmon's plan," and letters, corresponding to each division, head the special localities which they respectively include, given in the Flora. The number of species in Surrey is reckoned at 984, but this estimate includes a large proportion of introduced and naturalized species, which it was found too difficult to separate "with anything like certainty." We look, however, to authors and compilers of local Floras, for some indication as to the probability or otherwise of the species being indigenous, and as to the extent to which clearly introduced species have become naturalized within the areas upon the Botany of which they undertake to write, and we have a right to complain when these indications are withheld or loosely given. Botanists at a distance, or readers not used to such works, might fairly gather from page 7, for example, that the two Hellebores might he held as unquestioned natives of the county. Mr. Watson, however, himself a Surrey resident, tells us in his "Cybele," that the Surrey localities of one of the species are "very suspicious;" while, of the other, the localities which he has seen (whether in Surrey or elsewhere is not stated,) are none of them worth recording. Appendix C. upon the geological relations of Surrey plants is valuable, especially in connection with questions referred to in Mr. Baker's book. The formations which occupy the largest area of the county are the Bagshot Sand, London Clay, Chalk, Lower Greensand, and Wealden Clay. The number of species which are known to occur upon all the strata, including several not here enumerated, is 117.

Supposed to be confined to the London Clay 17

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Teucrium Botrys which is believed to be indigenous, is peculiar to Surrey, and the Box, Mr. Brewer states, is probably not thoroughly naturalized elsewhere. Lilium Martagon and Impatiens fulva are said to be completely naturalized.

N. H. R.-1864.

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We miss, in Mr. Brewer's book, a tabular comparison of the Surrey Flora with that of other comital areas; and we have no general view of the distribution of species through the county, excepting so far as the geological appendix supplies it. A list might also have been given, perhaps, of plants not yet found in the county, but which from their occurrence in adjacent counties, might be expected to occur there.

Mr. Preston's Flora is an enumeration of the species growing within a distance of six miles of Marlborough, drawn up principally for the use of those pupils of the Marlborough College, who may be favourably disposed to Natural History pursuits. Mr. Babington's "Manual" is followed in the arrangement, &c. of the species. Notices of the Birds found in the neighbourhood, and also a sketch of its Geological features, the latter by Mr. Adams, accompany the enumeration of plants, which appears to be carefully drawn up, and well suited for the purpose intended by its author. Brief diagnoses, however, of the Marlborough plants, on the dichotomous plan or otherwise, might easily have been introduced in the enumeration. This would have materially added to the usefulness of the work, and would have saved the Marlborough students the trouble of carrying a British Flora about with them in their botanical walks within the six-miles boundary. This little book may serve as a good nucleus for a future work, in which may be described the geognostic and stational relations of the species, &c.

VIII.—VEGETABLE HYBRIDITY.

(1.) NOUVELLES RÉCHERCHES SUR L'HYBRIDITÉ DANS LES VÉGÉTAUX: Mémoire couronnée par l'Académie des Sciences en 1862. Par M. Ch. Naudin. Deuxième Partie. Ann. Sc. Nat., Sér. iv. xix. 180.

(2.) DES HYBRIDES VÉGÉTAUX CONSIDÉRÉS AU POINT DE VUE DE LEUR FÉCONDITÉ ET DE LA PERPÉTUITÉ OU NON PERPÉTUITÉ DE LEURS CARACTÈRES. Par D. A. Godron. Ann. Sc. Nat., Sér. iv. xix. 135.

IN January, 1860, the French Academy of Sciences proposed the question of Hybridisation in the Vegetable Kingdom, for competition for the Physical Science Prize, to be awarded in 1862. Competitors were to find replies to the following:

In what cases are hybrids fertile inter se ?

Is their fertility in relation to the external resemblances of the species from which they are derived? or does it indicate some special affinity in respect of generation?

Is the sterility of hybrids due to an imperfection of the pollen? Are the pistil and ovules always capable of being fertilised? or are they sometimes imperfect?

Do self-fertilised hybrids retain their hybrid character unaltered? or do they return to one or other of their parent-types?

M. Ch. Naudin, a distinguished and laborious botanist, attached to the Jardin des Plantes, and M. Godron, Dean of the Faculty of Sciences at Nancy, also well known as a botanist, have been the only competitors. The first prize has been awarded to M. Naudin.

Of M. Naudin's Memoir, we have seen only the second portion, which includes, however, the discussion of the experiments detailed in the first part, their general results, and the replies of the author to the questions of the Academy.

The entire memoir is expected to appear in the "Recueil d. Mémoires" of the Academy. M. Godron's essay is given at length in the "Annales."

We do not find that the reliable results of the experiments detailed in these Memoirs add any important facts to our knowledge. They afford us a somewhat broader basis for generalisation than we possessed before, but yet not broad enough to enable us to venture far in that direction. The results of experiments are too often contradictory and conflicting to permit us to rest satisfied with what has been done in artificial hybridisation.* The conclusions of these observers, even with regard to one of the most important questions involved, are by no means in accordance.

M. GODRON SAYS Simple hybrids are absolutely sterile.

M. NAUDIN SAYS Hybrids are fertile whenever their

anthers contain well organized pollen. Of 30-40 hybrids experimented upon, ths were found to produce seeds capable of germination.

We would suggest to the Committee of Recommendations of the British Association, the propriety of appointing a Sub-Committee of Fertilisers, with a view to annual reports of further experiments on this subject upon an extended scale.

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