"Books and Current Literature. 



263 



perished, and a succession of such summers would necessarily 

 result in the replacement of mespphytic by xerophytic associa- 

 tions of plants. What is thus seen to be now taking place has 

 evidently been carried out on a far grander scale in earlier post- 

 glacial time. 



From a report of the British Vegetation Committee's excur- 

 sion to the west of Ireland (1908) it appears that in Connemara 

 the conspicuous plant formations are (1) the submerged and 

 reed-swamp vegetation of the numerous lakes, together with 

 wetter and drier "Flachmoor," (2) heath pasture or heath moo l 

 on drier hillsides of metamorphic rock, and (3) woodlands on 

 rocky islands or in sheltered ravines " These w^oods are regarded 

 as a higher stage in the succession from the heaths In com- 

 paring the vegetation of Connemara with that of northwestern 

 Scotland, it is noted that while peat is being rapidly formed in 

 west Ireland, denudation exceeds, growth in northern Scotland." 



Burck, in the Biologisches Centralblatt (XXVIII, 1908) 

 takes up anew Dai win's law of cross-fertilization in the light of 

 recent views concerning what is fundamental in fertilization, 

 and especially from what is known of plants with cleistogamic 

 flowers, which for periods wholly beyond reckoning have been 

 reproduced by self-fertilization without losing their constitu- 

 tional vigor and fertility. He concludes that floral. .biology has 

 departed farther and farther from the views held by Darwin. 



Vaeeari (Malpighia, XXII, 1908) presents the results of 

 his ecological observations on the flora of the Archipelago of 

 Maddalena, a group of small islands near the northern coast of 

 Sardinia, and concludes that judging from its flora this archipel- 

 ago may be regarded as the remnants of an isthmus which for- 



