Floristik, Geographie, Systematik etc. 331 



lences and re-actions. Blakeney with its shingle beach and salt 

 marshes is lavourable to the production ot" new habitats for coloni- 

 sation and is being utilised for exact studies on the sequence ot 

 different populations. The woodlands of Britain are admitted to be 

 an intricate puzzle difficult to compare with virgin forest of Ame- 

 rica. The problem of the moors and the possibilities of reclamation 

 are urged as an important task for the British ecologist. 



IX. Drude, O., The Flora of Great Britain compared 

 with that of Central Europa. (XI. p. 236 — 255.) 



This is an important comparison of the floras of two areas, in 

 some respects closely allied , but in other respects diverse; man}^ 

 details are given but probably the contribution has a still greater 

 value from the suggestions made as to the aims of future lioristic 

 work. In discussing species limits and local races, the author ex- 

 presses the opinion that many species Polymorphie in Germanj'- 

 look very different in England, and represent examples ot 

 local endemism. As regards floristic distribution, the author tinds 

 that at the lower altitudes the same species are more uniformly 

 distributed over the whole country, a ränge of 9 degrees of lati- 

 tude, than is the case in Central Ger man}'. It is not onl}' indi- 

 genous species which show this, but introduced trees ilke Arauca- 

 ria inibricata and Acer pseudoplatanus grow as well in the north as 

 in the south. Britain thus furnishes instances of vegetational li- 

 mits determined by developmental conditions raiher than by cli- 

 matic or ecological ones; migrations are not completed. Extensive 

 lists are given of species which occur in Britain and in West- 

 Central Europe, species remarkable for their absence in Bri- 

 tain, and German species with a noteworthy British distribution. 

 The origin of the British flora is briefly discussed. The arcticalpine 

 Clement is notheworthy because of the low altitude reached by man}»- 

 of the species, but there is also their concentration in detinite loca- 

 lities. The peculiarities of distribution are to be explained as a case 

 of colonisation during the Glacial Period, the present stations ha- 

 ving been occupied in the close of the Baltic ice period. The widely 

 varying habitats of Dryas octopetala are taken as an example of „a 

 perverse distribution and mixture of relict-stations." 



The structure of the plant formations is also compared. The 

 woodlands are notheworthy in the absence of native Pimis sylves- 

 tris in the south, also in their uniformity as regards dominant spe- 

 cies, but the ashwoods {Fraxiniis) a-re a distinct feature. The planls 

 of the undergrowth also furnish material for comment The hills 

 and moors of northern Britain, so frequently on summit-plateaux 

 with peat, and descending so low on the vallej' slopes to meet the 

 woodland which ceases at a low altitude, these are noted. The 

 lowland heaths, the aquatic formations, and the coast formations 

 are briefly dealt with. W. G. Smith. 



Pugsley, H. W., The genus Finnaria L. in Britain. (Journ. 

 Bot. Suppl. N'3s 589— 595^p. 1—74. 1912.) 



A continuation and summar}- of previous papers. The author 

 has since examined the Finnaria material in the majority of British 

 collections as well as much fresh material. In addition to Funiaria 

 Paradoxa, sp. nov. and F. neglecta, subsp. nov., the author describes 

 a new hybrid and several new varieties. M. L. Green (Kevv). 



