ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 627 



CRYPTOGAMS. 



Pteridophyta. 



(By A. Gepp, M.A. F.L.S.) 



Branching in the Ophioglossaceas.* — W. H. Lang gives an account 

 of branching in the OphioglossacefB, the comparison of which with the 

 branching known in the Zygopteridete and Hymenophyllaceae is of 

 special interest. Branches occur occasionally in all three genera of the 

 Ophioglossacea3— from lateral roots in Ophioglossum ; from dormant or 

 vestigial axillary buds which are always present in Hehninthostachys ; 

 from similar dormant buds in Botrychium Lunaria. The occasional 

 branches found in Botrychium and Helminthostachys are therefore not 

 adventitious. While not agreeing in detail with the branches of the 

 ZygopteridcEe, those of the Ophioglossacefe are clearly comparable 

 structures, and the study of their vascular supply strengthens the pro- 

 bability of a relationship between the two groups. 



Vascular Anatomy of the Ophiog'lossacese.f — W. H. Lang writes 

 oti the interpretation of the vascular anatomy of the Ophioglossaceaj. 

 The affinities of this group have long been a disputed question. At 

 first they were classed with the Filices, later with Lycopodiales and 

 Spheuophyllales. Xew evidence connects them with the Ferns, and 

 specially with the extinct group of the Coenopteridete (Botryop- 

 terideae and Zygopteridese). They also have features in common with 

 the existing Osmundaceai and Hymenophyllaces, which again exhiliit 

 affinities with the CoenopterideBe. The arguments in favour of the 

 above affinities are based largely upon the vascular relations of the 

 sterile and fertile regions of the leaf and the structure of the sporangia. 

 The general anatomy of the stem and leaf-trace has also been taken 

 into account ; but Lang now studies it more fully in the liglit of that 

 of the extinct Coenopterideffi, and finds that there is an essential similarity 

 in plan of stelar construction between the OphioglossaceiB and the Coeno- 

 pteridese. There is a real, though it may be a collateral, relationship 

 between the two groups. 



Metaclepsydropsis duplex.^ — \y. T. Glordon writes on the structure 

 and affinities of Metaclepsydropsis duplex, a Zygopterid fossil fern 

 obtained at Pettycur. The stem is a long dichotomously branched 

 rhizome, which emitted petioles and roots at very wide intervals. The 

 differentiation of the petiole-trace from its earliest stage, which is of 

 Diiieuron-\\\.Q type, is described. The pinna-traces are also studied. 

 The root-traces are diarch with a l)arrel-shaped xylem mass. The cortex 

 presents nothing of special note ; in stem and petiole, however, no 

 sclerencliyma is present. One specimen, probably abnormal, shows 

 secondary thickening ; it appears similar to Botrychioxylon. The author 



* Mem. Proc. Manchester Lit. Phil. Soc, Ivi. (1912) pp. xxxii-xxxiii. 



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



% Trans. Roy. Soc. Edinburgh, xlviii. (1912) pp. 163-90 (4 pis. and figs.). 



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