500 SUxMMARY OF CURRENT RESEARCHES RELATING TO 



rhizome must be referred. The distmction which can be traced between 

 inner and outer primary xylem throughout the plant is of importance. 

 The pith is wholly intrastelar, and the internal endoderrais is a new for- 

 mation. The leaf-trace exhibits a tendency to complete its ring of 

 xylem by a development of adaxial tracheides. 



Vascular Anatomy of the OphioglossacesB.* — W. H. Lang dis- 

 cusses the affinities of the Ophioglossace^. At first classed with the 

 ferns, and later with the Lycopodiales and Sphenophyllales, they are now 

 included among the Ferns and are thought to show special relationship 

 with the extinct Ccenopterideae (Botryopteridese and Zygopteridese) ; 

 and they have features in common with the Osmundace^ and Hymeno- 

 phyllacete. The evidence is derived from the vascular relations of the 

 sterile and fertile regions of the leaf, the structure of the sporangium, 

 and the general anatomy of the stem and leaf -trace. Lang discusses the 

 chief features of the vascular anatomy in this preliminary paper, not 

 dwelling on details but seeking to interpret the facts. He finds an 

 essential similarity in plan of stelar construction between the Ophio- 

 glossacese and the Coenopteridege. These two groups appear to throw 

 mutual light on one another as regards morphology and anatomical 

 structure ; and there appears to be a real relationship, though perhaps 

 collateral, between them. 



Periderm of Fossil Lycopods.t — M. H. Kisch writes on the 

 physiological anatomy of the periderm of fossil Lycopodiales. She finds 

 that the periderm of the fossil Lycopod attained a great and conspicuous 

 development. It is of the nature of secondary cortex, and is morpho- 

 logically phelloderm. The cells are prosenchymatous, but in some 

 species are subdivided — such subdivision, carried to an extreme, pro- 

 duces Dictyoxylon cortex. Concentric zones may occur in the periderm 

 owing to differences in the nature of certain layers of cells. The peri- 

 derm forms a complete and apparently continually increasing cylinder 

 near the periphery of the organ, and seems to have served as the main 

 supporting tissue of the stems, for which it was well qualified by its 

 physical properties. Besides its mechanical function it possibly acted 

 as a reserve storage tissue, for which there is no adequate provision 

 elsewhere than in the cortex. The periderm does not appear to have 

 become the outermost tissue, and is not primarily a protective integument 

 as is the periderm of recent plants. 



Protocorm of Lycopodium. J — L M. P. Browne comments on J. E. 

 Holloway's comparative study of six New Zealand species of Lycopodium, 

 in respect of the protocorm and of the anatomical structure of the stem. 

 Holloway's account of the protocorm in Lycopodiiun laterals adds con- 

 siderably to our knowledge of a puzzling organ. In this species it 

 attains a fairly high development, and becomes a sort of rhizome bearing 

 several protophylls, and capable of branching and of giving rise to a 

 stem from each branch. Vascular tissue penetrates for some distance 



* Mem.Proc. Manchester Lit. and Phil. Soc, Ivi. (1912) No. 12, 15 pp. (6 figs.). 

 t Ann. of Bot., xxvii. (1913) pp. 281 -320 (1 pi. and figs.). 

 X New Phytologist, xii. (1913) pp. 222-5. 



