RECENT ADVANCES IN SCIENCE 557 



radial rows of cells. Its production only appears to take 

 place in parts which have been submerged in mud or water, 

 the former producing the most marked effect.- Miss Collins 

 (Proc. Linn. Soc. N.S. Wales) describes the anatomy of the 

 leaves of Sccevola crassifolia, a sand-dune plant belonging to 

 the Goodeniaceae. The leaves assume a vertical position, 

 and are large and fleshy, the palisade and central regions 

 respectively containing occasional branched mucilage cells 

 and water-storing tracheids. When young the leaves bear 

 numerous capitate glands whose resinous secretion serves for 

 the protection of the juvenile foliage within the bud. This 

 secretion ceases, however, as the leaves approach maturity. 



Taxonomy. — Dr. Wernham (Journ. Botany, Nov.) describes 

 new species of Rubiaceae belonging to the genera Mussenda 

 Sabicea, Stipularia, Tricalysia, Vangueria, Cuviera, Ixora, 

 Rutidea, Globulostylis, and Amaralia. In the same journal 

 Mr. Grove describes new species of fungi belonging to the 

 genera Ceuthospora, Ascochyta, Diplodina, Melasmia, and 

 Glceosporina. Further species of Uredinaceous fungi are 

 described by J. C. Arthur (Amer. Journ. Bot.) for the following 

 genera : Ravenelia (5 spp.), Uropyxis, Skierka, Pucciniosira, 

 Uromyces (3 spp.), and Puccinia (12 spp.). A new genus of 

 Ccelastraceje, Eutetramonas, is described by L. B. Walton 

 {Ohio Journ. Science, Feb. 1 8). 



Morphology. — The Phyllode theory of de Candolle, which 

 conceived the leaf of the Monocotyledons as the equivalent of 

 the leaf-base and petiole of the Dicotyledons, has been revived 

 and elaborated in an extremely interesting paper by Mrs. 

 Arber {Annals of Botany, Oct. 191 8). The author points out 

 that this theory affords an explanation of the parallel venation 

 of the former group which is also met with in the phyllodic 

 structures amongst Dicotyledons. This interpretation is applied 

 also to the monocotyledonous cotyledon, and support is 

 given to the hypothesis of Henslow that the leaf-blades of 

 Sagittaria, Arum, etc., are " pseudo-laminae " developed from 

 the phyllode apex. The chief contribution of the paper under 

 review to this vexed question is a consideration of the anato- 

 mical evidence. It is pointed out that some petioles are 

 characterised by the possession of inversely orientated bundles, 

 which feature is also met with in some, though not all, dico- 

 tyledonous phyllodes. Inverted bundles are only known to 



