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NOTICES OF BOOKS. 



appear, but that those which in the dry climate only grew on the wet 

 soil will, in the wet climate, grow also on the dry soil. 



Prom these considerations Mr. Baker proceeds to sketch out the 

 surface of Great Britain as characterized by its geological structure, 

 and (as is assumed) its consequent superficial soil, of which he re- 

 cognizes six principal modifications ; for these we must refer to his 

 Essay, with the casual remark that we find no allusion to the pheno- 

 mena of the " drift," which, we believe, in many places spreads the 

 detritus of rocks easily disintegrated over immense surfaces, coloured 

 in our geological maps as having a very opposite subjacent rock, and 

 which, if we are right in our supposition, must introduce a disturbing 

 element into Mr. Baker's calculations. 



A co-ordination of these data with Watson's botanical provinces and 

 zones follows, from which the Author proceeds to classify his facts, ar- 

 ranging the British plants under thirteen heads, of which the most 

 important to notice are those including — 1, the species common to all 

 soils (700 sp.); 2, those having a marked preference for soils disin- 

 tegrated with difficulty (92 sp.) ; and 3, those with a marked pre- 

 ference for soils not easily disintegrated (144 sp.). The other divisions 

 include plants that, for special reasons, are not included under any of 

 the above : there are modifications of these heads ; as. Maritime, Hiber- 

 nian and Sarnian, local or dubious, agricultural aliens and introduc- 

 tions, horticultural aliens and introductions. 



To many of the species thus ranked we might take exception, as 

 with regard to the Hellebori, Clematis, Atropa, Sesleria, having a 

 marked preference to soils with difficulty disintegrated, seeing that 

 some of these flourish in the deep beds of stiff clayey " drift" in Suf- 

 folk and elsewhere, and the Sesleria on schist rocks in some parts of 

 Scotland; as also to the introduction of such water-plants as Is- 

 nardia, Elatine, and other absolute aquatics, into the list of species 

 supposed to have a marked preference for soils easily disintegrated ; 

 and though in favour of generalizing upon strong indications of pre- 

 ference for certain soils or climates, in subjects like this, where ab- 

 solute data are almost inaccessible, yet we cannot help remarking that 

 of 1015 species only 92 are quoted as very strongly indicative of one 

 kind of soil, and 144 of the other, numbers which might be consi- 

 derably reduced without violence to facts. 



Lastly, the Author opens the most important and curious question, 

 the modification of specific type through the influence of the soil, and 



