110 Pteridophyten. — Floristik etc. 



the stem, primary xylem, phloem and cortex, cambium, secondary 

 phloem and cortex. The increase in diameter of the rhizophoric 

 lobes leads to a considerable amount of decortication. The present 

 authors agree with Farmer in regarding the root as adventitious; 

 they, however, enunciate a fresh and complicated theory as to the 

 development of the roots on the rhizophore: these are held to be 

 produced by the primary rhizophoric meristem in rows or series, 

 the series arising acropetally. Each series contains roots of the 

 same age, but these reach the surface of the stem at different times; 

 the nearer to the long axis of the lobe of the rhizophore a root is 

 developed the narrower is the zone of the cortex it has to traverse 

 before reaching the exterior. As the result of more rapid centripe- 

 tal production of cortical cells at the centre of the lobe such roots 

 are carried towards the outer margin of the lobe and the remaining 

 members of the series emerge continuously nearer and nearer to 

 the angle of the furrow. The oldest series of roots on a lobe always 

 consists of a Single root which is destroyed ear]y by decortication. 



After summarizing the subdivisions of the genus Isoeies put 

 forward by previous systematists the writers point out the arbitra- 

 riness of the suggested classifications. They apparently regard the 

 genus as consisting of very closely allied species and suggest its 

 division into Eu Isoetes characterised by wide, thick-walled lacunae 

 in the leaf, by closely similar fertile and sterile leaves and by an 

 absence of phyllodia and into Cephaloceratonj characterised by 

 narrow, thin-walled lacunae in the leaf, by sporophylls larger that 

 the vegetative leaves and by the constant production ofphyllopodia. 



As regards the systematic position of Isoetes it is held that 

 *Campbeirs Suggestion, adopted by Lotsy, should be accepted 

 and Isoetes be placed in a separate class, that of the IsoetaleSj coor- 

 dinate with the Lycopodiales, Eqtiisetales, Sphenophy Haies and Fili- 

 cales. The authors contend that the likeness to the Lepidodendra- 

 ceae and Sigillariaceae has been overrated and point out that even 

 the lobed root-bearing region of the stem of Pleuromeia bears only 

 a superficial resemblance to the peculiar root-bearing region of the 

 stock oi Isoetes. Isabel Browne (London). 



Merrill, E. D., Reliquiae Robin sonianae. (Philipp. Journ. Sc, 

 C. Botany. XI. p. 243—272. Sept. 1916.) 

 Contains as new: Microthelia gregaria G. K. Merr., Phylloporina 

 multipunctata G. K. Merr., Arthronia Robinsonii G. K. Merr., Vin- 

 centia Robinsonii, Piper gelalae C.DC., P. nudiramum C.DC., Ficus 

 Henschelii, F. Hasskarlii, Exocarpus amboinensis, Elatosteniatoides 

 polioneuruin {Elatostema polioneurum Hall, f.), Henslowia Robinsonii 

 and Horsfieldia bivalvis Hook. f.). Trelease. 



Paul , H.. Flora einiger Moore inderOberpfalz. (Denkschr. 



kgl. bot. Ges. Regensburg. XII. N. F. VI. 26 pp. des Separatums. 



1 Taf. 1913.) 

 Die Moore der Ob erpfalz sind recht wenig erforscht. Das 

 grösste Gebiet ist das Vilsmoorgebiet bei Vilseck. Die Zahl 

 der an der Verlandung beteiligten Pflanzen ist beträchtlich, die 

 Typen wechseln Schritt auf Tritt, bestimmte Zonenfolgen fehlen. 

 Die wichtigsten Verlandungstypen sind: Phra^mites communis. 



