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Reviews and Book Notices. 



lig-ht not only on the long vexed problem of the nature of the 

 motion in the allied branch of the Diatomacea?, but also on 

 the question of direction of g-ermination in the veg-etable 

 king-dom generally. The quotation from Warming that the 

 movements are due to the 'protrusion of a mucilaginous stalk' 

 would, however, be less misleading to novices if it had a mark 

 of interrogation appended. As it is, they might think the 

 suggestion had the author's approval. 



Another luminous paragraph is that on ' Phylogenetic 

 Relationships.' Taken together with the unique 'Genealogical 

 Tree' on p. 22, it gives a strikingly clear description of the 

 position of Desmids in the Vegetable Kingdom. 



The illustrations are mostly original, and they do much 

 credit to the skill and accurate observation of the artist 

 (Mr. G. S. West). The reproduction of his drawings has also 

 been highly successful, and very few similar works on Natural 

 History can compare with this in truth and delicacy, which are 

 the elements of beauty. R. H. P. 



How to make a Rock-Soil Flora. By E. Adrian Woodruffe 

 Peacock. Goulding-, Louth, is. 20 pp. 



This short paper by a keen field-botanist contains suggestions 

 of interest to all botanists. Many will agree with the opening 

 sentence : ' No such thing as an ideal flora exists for a Watsonian 

 county or vice-county.' From a page of somewhat sweeping 

 assertions, we gather that the author proposes with the aid of 

 the Geological Survey Drift ^laps and by outdoor observations 

 to record the species of plants peculiar to the various rock-soils 

 of a district. This aim is ideal, but, as the author says : ' It is 

 absolutely useless to begin making notes with a view to a soil- 

 flora, till we have perfectly clear ideas about rock-beds, etc' 

 Herein lies the crux of the whole question. The table of soils 

 given in this paper is probably as good as any other, but its 

 application in the field will prove hard to any but an expert 

 g'eologist. The Drift maps do not give the necessary information, 

 and they are only issued for sale for small areas of Britain, while 

 the small scale only allows the larger patches of drift to be 

 shown. In spite of the difficulties of the subject, the author 

 contrives to convey much information which is all the more 

 valuable because it is largely self-acquired and is the result of 

 experience. The niethods of taking' notes (which cannot be 

 summarised here) are worthy of imitation. The author uses too 

 many contractions, but he does not expect others to do so : — 



Naturalist, 



