412 



NATURE 



{_MarcIi 3, 1887 



Rubusfntticosus,-JSi6i by including a large number of plants 

 that have no claim to be considered as really wild, such 

 as Linaria Cyinbalaria, CorydaUs luiea, and the wall- 

 flower. Mr. Watson's estimate was 1425, and, as com- 

 pared with this, the flora of Leicestershire will stand at a 

 little over 700. He worked out carefully in detail the 

 distribution over the island of all these species, and 

 showed that they fall into, broadly speaking, three geo- 

 graphical or climatic groups : that 532 species are spread 

 generally over the whole island ; that 606 species repre- 

 sent southern climatic and geographical influences ; and 

 that 238 species represent the boreal element in our flora, 

 and are plants that are thoroughly at home only in the 

 north of Scotland, and are found in England and Wales 

 only in mountainous tracts. In any county, or other 

 tract of land, the great mass of the flora always consists 

 of the 532 generally-diffused plants, and the chmatic 

 difference between one county and another is shown by 

 the extent to which the characteristically northern and 

 southern types are represented. It adds very much to 

 the interest which any book on local botany has for the 

 non-resident general reader, if the writers keep these 

 three climatic groups distinct in their minds, and give as 

 complete an idea as possible of the way in which, and the 

 extent to which, the austral and boreal types are repre- 

 sented in the area of which they treat. The writers of the 

 present " Flora " have not attempted to give any general 

 summary worked out upon this basis, and they are quite 

 mistaken in supposing that their county includes three 

 out of Watson's six climatic zones. Watson's infer- 

 agrarian zone includes the low-level country south of the 

 Humber and the Dee. Its characteristic types are such 

 plants as Clcmalis Vilalba, Rubia peregrina, Geranium 

 rfltundifoliuiii, Trifolitiin subterraneum, T. suffocatuin. 

 Lathy rus Nz'ssoh'a and L. Aphaca, and C C7itaiirea Calci- 

 trapa. Watson's mid-agrarian zone inclu des the low levels 

 of the north of England, up to a height of 900 feet above 

 sea-level on the mountains of Yorkshire and the Lake Dis- 

 trict. Its upper limit is marked by the cessation (essen- 

 tial from climatic causes, not accidental) of fruticose 

 Rubi, Rosa atvc/isis, Pyrus Mains, Vibiirntim Opuhis, 

 and Abuis gliitinosa. Above this, up to the line of pos- 

 sible arable cultivation, e.vtends the super-agrarian zone, 

 with an average annual temperature of 42° to 45° F. 

 The only county south of the Humber and Trent in 

 which it is represented is Derbyshire. There do not 

 appear to be in Leicestershire more than ten or a dozen 

 out of the 238 boreal plants, such as Lycopodium Selago, 

 Enipetritin niorum, and Drosera anglica, and these are 

 either very rare or quite extinct. There is no saxifrage 

 except granulaia or iridactylitcs, no wild bird-cherry, no 

 And7'ccea, no Polypodium Phegopterisox Dryopteris. To 

 understand their county and its flora in their proper rela- 

 tion to the rest of England, IVIr. Mott and his colleagues 

 must revise completely their ideas on this subject. The 

 county would appear to be essentially a mid-agrarian 

 outpost, pushed out from the Pennine Chain into the 

 centre of England ; for, out of the 600 austral types, 

 not more than about 150 enter into it, which is fewer than 

 there are either in North Yorkshire or at the Lakes. The 

 limestone types, the occurrence of which is regulated 

 more by soil than climate, appear to be well represented. 

 For the way in which the details of the flora are worked 



out, we have nothing to give but commendation. In the 

 identification of the Phanerogamia, great pains has evi- 

 dently been taken by the Committee. No doubt some 

 of the species, which they admit on the authority of their 

 predecessors, will prove to be blunders, as, for instance, 

 Tofieldiapalustris, Cardiacs heterophylliis, and Asplcniiim 

 viride. When the members of the county society make 

 their excursions into the different districts, they will be able 

 to see at a glance what plants have been gathered there by 

 their predecessors. The flora includes, not only the Phane- 

 rogamia and ferns, but also the mosses, Hepaticse, lichens, 

 Algae, and fungi. It is not likely that there are many 

 fresh Phanerogamia or ferns still to find ; but as only 4 

 Characeffi, 179 mosses, 49 Hepaticffi, 177 lichens, and 

 446 fungi are known, there is ample scope for further 

 work in all these orders. jThe portion of the book devoted 

 to Alga;, which is ably edited by Mr. F. Bates, of Leicester, 

 contains descriptive notes on many of the less known 

 species. There is an interesting note on p. 344, on the 

 species which have become extinct. They are 30 in 

 number, and are nearly all plants of swamps and heaths, 

 amongst them he^wg Lycopodium Selago, Osmi/nda regalis, 

 Pinguieula vulgaris, Drosera anglica, and D. rotundifolia. 

 The book will be still more interesting when we have 

 good floras of Warwickshire, Nottinghamshire, Derby- 

 shire, and Cheshire to compare it with, and for all these 

 counties " Floras " are in course of preparation. 



J. G. B.^KER 



GEOLOGY OF JERSEY 

 Gcologie dc Jersey. Par Le P. Ch. Noury, S.J. (Paris : 

 F. Savy ; Jersey: Le Feuvre, 1886.) 



CONSIDERING that Jersey became subject to the 

 Crown of England at the time of the Norman 

 Conquest, English geologists may agree with M. de 

 Lapparent's complaint as to the neglect the island has 

 hitherto received. Although the Geological Society of 

 London made it their earliest care to publish in 181 1 (not 

 1817, as quoted in the opening of this little volume) Mac- 

 CuUoch's paper on the Channel Isles, although at the 

 present time more than one worker is engaged in further 

 removing the reproach, M. Noury is even now well to 

 the front in providing in a handy form an account of the 

 structure of Jersey serviceable to inhabitants and visitors 

 alike. The character of this well-printed brochure pre- 

 supposes, however, some general knowledge of geology, 

 and the author is perhaps not so uniformly happy as, let 

 us say, the Rev. W. S. Symonds in placing his facts 

 before the intelligence of the untrained tourist. Some 

 controverted matters, moreover, of purely speculative 

 value are introduced,. such as the construction of the 

 primitive crust (p. 126), the succession in time of granite, 

 syenite, and diorite, and the formation from these of 

 schists and gneisses by disintegration in a heated ocean. 

 The description of the prevailing rocks is the work of a 

 close observer in the field ; and the careful mention of 

 such materials as have been artificially introduced (" culti- 

 vated rocks," one might almost call them) cannot be too 

 highly praised. Future geologists will thus be spared 

 the description of gneissic fragments (p. 6) imported as 

 ballast from Brazil. 



The suggested derivation of " pyromeride " (p. 29) — 



