120 The Plant World. 



Guelinger, in the Beihefte Bot. Cbl., 1909, brings to com- 

 pletion his extended study of the distribution of plants in the 

 limestone region of the southern Alps. Orographic, hydro- 

 graphic, geologic and climatic factors are discussed in their 

 relation to the various types of vegetation, each of which is 

 considered at length under the several formations, or associa- 

 tions, belonging to it. In conclusion, four vegetative regions 

 are distinguished as follows : 1 . The submontane region, with its 

 upper limit at 1,000 to 1,050 meters, the forest cover of which 

 is characterized by the oak-hornbeam, and chestnut associa- 

 tions. 2. The montane region, from 1,050 to 1,700 meters, 

 distinguished by beech forest and meadow. 3. The subalpine 

 region, the upper limJt of which is placed at 1,900 to 1,950 meters, 

 less sharply defined than the preceding, but characterized, in 

 part, by its larch forest and several associations of shrubs which 

 here reach their upper limits. 4. The Alpine region. 



Herzog has recently published (Engler's bot. Jahrb.) an 

 account of the vegetation of vSardinia in which both the plant 

 associations and geographical relations are discussed at length. 

 The Sardinian flora includes 1,560 species of Phanerogams and 

 Vascular Cryptogams, of which 613 are classed as Mediterranean, 

 78 west Mediterranean, 115 south Mediterranean, 49 tyrrhene, 

 and endemic in Sardinia, 16. There remain 678 species classed 

 as non-mediterranean, including numerous widely distributed 

 grasses, water plants and cosmopolitan species. Comparison 

 of the flora with those of Corsica and Sicily shows that they are 

 fundamentally alike in their Mediterranean elements and that a 

 considerable number of endemic species are common to these 

 three islands. A nearer relationship of older endemic species is 

 noted betw^een the floras of Corsica and Sardinia than between 

 those of the latter and Sicily; but the exclusively insular and 

 younger endem.ic species show a greater nearness between Sar- 

 dinia and Sicily, as if their floras had developed largely in more 

 recent times under similar conditions. The composition and 

 peculiarities of the alpine floras suggest that in Sardinia the 

 settlement of alpine elements took place before the separation of 

 the two islands, while in Corsica their migration continued much 

 longer. 



