568 Anatomie. — Cytologie und Befruchtung. 



Moorfrage und speciell der schweizerischen Moore zusammen 

 und wird für diese Fragen für lange Zeit massgebend sein. 



M. Rikli. 



Beer, Rudolf, The present position of cell- wall re- 



search. (New Phytologist. Vol. III. No. 6 and 7. p. 159. 



1904.) 



The article gives a brief review of some of the principal 



directions along which research into the Constitution of the 



cell-wall has moved during the past few years. 



It summarizes the more recent views held upon the Chemi- 

 cal nature of the celluloses, pectic substances, cutin, suberin 

 and lignin, and also upon the Constitution of the membranes 

 of various fungi and mosses. Finally a short account is given 

 of the latest contributions to the study of the manner of for- 

 mation of the cell-wall by the protoplast and its subsequent 

 growth and differentiation. d. T. Gwynne-Vaughan. 



CHANDLER, S. E., On the Arrangement of theVascular 

 Strands in the „Seedlings" of certain Lepto- 

 sporangiate Ferns. (New Phytologist. Vol. III. No. 5. 

 p. 123. 1904.) 



A preliminary notice of a study in the development of the 

 vascular System in a considerable number of Ferns, a füll account 

 of which is about to be published. The plants examined re- 

 presented some twenty genera, and the earlier stages in all 

 were found to be very constant. At the base of the stem a 

 solid protostele is present. Higher up parenchyma cells appear 

 at the centre of the rod followed quickly by sieve-tubes. Then 

 the first leaf-traces depart which, however, do not form any 

 real leaf-gaps; in other words „the ground-parenchyma does 

 not „encroach upon" the vascular tissue, but merely replaces 

 the xylem and phloem thus temporarily interrupted by the 

 departure of the leaf-trace". In the subsequent differentiation 

 two related types are recognized in the Polypodiaceae. In the 

 first an elementary dictyostelic structure is arrived at imme- 

 diately. In the second a „ground-tissue pocket" appears in 

 connection with the fifth, sixth or seventh leaf-trace. In Poly- 

 podlum aureum the cauline Strand divides directly into two, 

 however, the writer hopes to shew that its vascular System is 

 essentially phyllosiphonic in character. The general results 

 support the contention that in all so-called „stelar" questions, 

 we have to confine our attention to the consideration of tissues 

 of two, and only two categories, viz., vascular and non-vas- 

 CUlar. D. T. Gwynne-Vaughan. 



Davis, Bradley Moore, Oogenesis in Vaucheria. (Botanical 

 Gazette. Vol. XXXVIII. 1904. p. 81—98. Plates 6—7.) 



The form studied was Vaucheria geminata, var. racemosa. 

 The fixing agent was a weak chromo-acetic acid (1 per cent. 



