ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 67 



conjunctive parenchyma cells of the vascular bundles of the petiole, 

 which replaces the first-formed elements of the wood, sometimes by 

 simply crushing the spiral vessels, bat generally bv means of tvlose-like 

 swellings within the cavity of the vessels. True tyloses are unknown in 

 recent Vascular Cryptogams, save in two rare cases. As regards the 

 pseudo-parenchyma in the tracheids of fossil ferns, for example, in the 

 petiole of Rachiopteris insignis (Zygopteris corrugata), the evidence that 

 it is composed of fungal hypha?, is at least as strong as that it is a true 

 process of tylosis. 



Abnormality in Psilotum triquetrum.*— M. G. Sykes describes 

 and figures an abnormal sporangiophore structure noticed on a dried 

 specimen of Psilotum triqmtrum from New South Wales. Some 

 distance below the apex there occurred, among the ordinary synangia, a 

 cluster of four synangia borne together on a common stalk. * Three of 

 these synangia were bilocular, while the apical or terminal one was 

 unilocular. The two lower synangia were subtended each by a double 

 bract, the third synangium by a single bract, and the apical by no bract. 

 She is inclined to regard it rather as derived from a single proliferated 

 synangium-bearing appendage than as equivalent to a normal aerial 

 branch abortive in development. 



Structure of a Branch Cone in Equisetum.t— W. Stiles describes 

 the structure of an abnormal cone of Equisetum maximum in which 

 branching of the strobilus had occurred. The most interesting feature 

 was the presence of vascular bundles in the pith of the main axis, quite 

 unconnected with the normal ring of vascular tissue, and having a 

 structure different from that of the normal bundle. It is possible that 

 these medullary vascular strands may be the remnants of the solid 

 central stele of the ancestors of the living species of Equisetum. 



Origin of the Sphenophylleae.J — 0. Lignier in 1903 attributed to 

 the Equisetales and Sphenophyllales a Filicinean origin. In reply to 

 objections urged by Scott and Sykes against this view, Lignier now 

 reaffirms his position with additional argument. The " fertile leaves " 

 of Sphenophyllum cannot be homologised with the sporangiferous 

 structures of Tmesipteris ; but their " sterile pinnules " are comparable 

 with those of Arclmopteris. The "fertile pinnules" are of the same 

 type as those of the Primofilices. Hence Lignier concludes that the 

 Sphenophyllete should be attached to the Primofilices, and not to the 

 Lycopodiales. 



Fossil Ferns. — F. Weiss § publishes an abstract of a paper on tl e 

 morphology of Stigmaria and of its appendages in comparison with 

 recent Lycopodiales. 



R. Kidston and D. T. Gwynne-Yaughan|| publish a second article 

 on the fossil Osmundaceas, describing the anatomy of a new genus 

 ZaJesskga with two species. 



* 



Ann. of Bot.. xxii. (1908) pp. 525-6 (figs.). 

 t XewPhvtolog., vii. (1908) pp. 113-16 (figs.). 



X Bull. Soc. Bot. France, iv. (1908) pp. 278-88. See also Pet. Gaz., xlvi. 

 (190S) p. 319. § Proc. Linn. Soc., 1907-8, pp. 74-5. 



|| Trans. Roy. Soc. Edinburgh, xlvia, (1908) pp. 213-32 {i pis.). 



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