360 Floristik, Geographie, Systematik etc. 



tiges, that is, in the presence of isolated species or small groups 

 which appear to be the last remnants of various migrants or passed 

 floras, it is an interesting speculation whence came those forms and 

 what topographical conditions of past ages they may indicate." The 

 theory of the continuity of land between Tasmania and Fuegia, 

 by way of antarctic or subantarctic regions, during comparatively 

 recent times, has already been put forward, and the author cites 

 various plant groups where close affinity is to be found between 

 the fioras of temperate South America and Tasmania. More- 

 over he conslders it possible that a stud}^ of fresh water Algae, 

 especially Desmids would give valuable evidence. But the plants 

 which give the most wheighty evidence are those belonging to the 

 genus Fagus, of which the group NotJwfagus is found only in 

 Fuegia, New Zealand, Tasmania and S. E. Australia. The 

 differences between Fagus (the northern beeches) and Nothofagus 

 (southern beeches) are regarded as being too small to allow of the 

 two groups having independent origin, therefore it must be con- 

 cluded that their distribution was once continuous across equatorial 

 regions. The seeds of the beech are not adapted to transport to 

 any considerable distance by sea or wind and though beeches 

 now require a temperate climate, evidence is brought forward to 

 show that there is uncertainty in inferring that beeches of former 

 days must necessarily have had a similar Constitution. Also some 

 of the beeches of Fuegia are infested with a unique fungus para- 

 site, Cyttaria, the only relation of which is found on the beech of 

 Tasmania. Again strong evidence of a high land connection is 

 to be found in the presence of deciduous beeches in both Fuegia 

 and Tasmania. It is generally supposed that the deciduous habit 

 is acquired by plants, subject to regulär dry periods or to periods 

 of ph vsiological dryness, but this is not always so. And in this 

 case it is more probable that „the complete absence of effective 

 light for many months has rendered the winter shedding of leaves 

 and rapid exposure of young foliage in the returning spring, fea- 

 tures of vital importance"." Therefore it is to be assumed that ever- 

 green beeches of Fuegia and Tasmania are the normal type and 

 the deciduous beeches of Fuegia and Fagus Giinnii of Tasmania 

 are recent products within the Antarctic Circle. E. M. Cotton. 



Safford, W. E., Proposed Classification of the genus Rol- 

 linia, with descriptions ofseveral new species. (Journ. 

 Washington Acad. Sei. VI. p. 370—384. f. 1—3. June 19, 191ö.) 



Contains as new: Rollinia deliciosa, R. Pittieri, and R. Jimenesii. 



Trelease. 



Schröter, C. Der Alpen wan d erer und die Alpenflora. 

 (Alpina. Mitt. Schweizer Alpen Club. XXIV. 4. p. 63-74. 4^». 1916.) 

 Verf. behandelt die Alpenflora zunächst in ihrer Bedeutung 

 für die Schuluno- der Beobachtung und dann als Orientierungsmittel 

 über Höhen und geologische Verhältnisse. Von den verschiedenen 

 Höhen stufen interessieren in erster Linie die über der Wald- 

 grenze crelecrenen Gürtel bis zu den höchsten Gipfeln (Strauchgür- 

 tel Mattengürtel, Pionierrasengürtel, Polsterpflanzenmatenal, Flech- 

 tencrürtel) wobei aber die absolute Höhengrenze m Metern über 

 dem Meer ausserordentlich wechselt, wie aus den herbeigegebenen 



