Palaeontologie. — Euraycetes. — Pteridophyten. — Floristik etc. 295 



comparison of the structural material of Masocarpon with the 

 incrustation remains of Sigillariostrobus, indicate that Masocarpon 

 belonsfed to Sigillaria. Agnes Arber (Cambridge). 



Arthur, J. C, Uredinales of Guatemala, based on Collec- 

 tions by E. W. D. Holway. (Amer. Journ. Bot. V. p. 325-336. 

 June 1918.) 



Contains as new Coleosporium domingensis (üredo doffritigensts 

 Berk.). Trelease. 



Bower, F. O., On Leaf- Architecture as illuminated by a 

 Study of Pteridophyta. (Trans. Roy. Soc. Edinburgh. LI. 3. p. 

 657—708. 1 pl. 31 textfigs. 1917.) 



After an historical survey of the literature, the author proceeds 

 to a detailed description of the architecture of leaves of the Pteri- 

 dophyta with special reference to their primordial leaves. This has 

 never been attempted hitherto, and this section of the paper, with 

 its nuraerous clear illustrations, constitutes a particularly valuable 

 contribution. The author regards the 'leaves' of the Lycopodiales 

 as falling into the category of true leaves, a point in which he 

 is in disagreement with Lignier. In the case of the Filicales 

 he shows that there is, as a rule, greater similarity in the juve- 

 nile leaves than in the adult leaves. In the former dichotomy, 

 either with equal branching or sympodially developed, is in most 

 cases a quite obvious feature. The paper concludes with a compa- 

 rative study of the data to which it would be impossible to do 

 justice in a brief summary. But it may be noted that the working 

 hypothesis is finally adopted that, except in such cases as are pro- 

 babh" reduced, the progressive stages seen with varying complete- 

 ness on the successive juvenile leaves of the individual, and reflec- 

 ted by the comparison of the adult leaves in various early vascular 

 types, indicate the stages of elaboration which prevailed in the 

 evolution of foliar structures in the sporophyte. 



Agnes Arber (Cambridge). 



Braun-Blanquet, J., Die Föhrenregion der Zentralalpen - 

 täler, insbesondere Graubündens, in ihrer Bedeu- 

 tung ftir die Florengeschichte. (Sep.-Abdr. Verh. Schweiz. 

 Naturf. Ges. 98. Jahresvers. Schuls, II. 28 pp. 1916.) 



Die zentralalpine Föhrenregion durchzieht die Zentralalpen von 

 den Seealp,en bis nach Kärnten. Sie umfasst in den rätischen 

 Alpen das Rheintal von Landquart bis unterhalb Disentis, 

 das vordere Schanfigg, das Albulatal bis zum Bergüner- 

 stein, das Unterengadin von Zernez abwärts nebst den 

 tirolischen Oberinntal und verläuft nach oben im Churer 

 Rheintal bei 1000 m, im Unterengadin bei 1400 — 1500 m. Der 

 gesamte Föhrenbezirk liegt innerhalb der Isohyeten von 50 — 100 cm 

 Jahresniederschlägen. Die durch ihren continentalen Klimacha- 

 rakter ausgezeichnete Vegetationsregion ist zugleich eine biogra- 

 phische Region (Hebung der Siedelungs- und Kulturgrenzen!). 

 Pflanzengenetisch ist sie gekennzeichnet durch zahlreiche, meist 

 lokalisierte Neo-Endemismen pontischer oder mediterraner Abstam- 

 mung. (Unterengadin: Rosa rhaetica, Hieracium florentinutn ssp. 

 anolasium , Iris squalens var. rhaetica, Centaurea maculosa var. Mu- 



