ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 73 



CRYPTOGAMS. 



Pteridopliyta. 



Leaf-architecture as Illuminated by a Study of Pteridophyta. — 

 F. 0. Bower (Tratis. Roij. Soc. Edinb., 1916, 51, 657-708, 1 pi. 

 and figs.). There are three chief avenues which may lead up to a 

 scientific knowledge of leaf -architecture. 1. A comparative study of 

 adult leaves (mature or while developing) of many different types, 



2. A study of the juvenile leaves of an individual, tracing the gradual 

 stages up to the adult form ; the results in various forms, related or 

 otherwise, may then be made, especially those of more primitive types, 



3. The results of such studies may be compared with the fossil record, 

 and conclusions obtained as to phyletic progression. The second avenue 

 has been somewhat neglected, especially in the Pteridophyta. In the 

 present paper the juvenile leaves of this group are studied and compared 

 with results obtained from other sources. A long summary of compara- 

 tive conclusions is given, and a postscript on theories of the ultimate 

 origin of the leaf. A. Gepp. 



Maceration of Carboniferous Plant-remains.— K. Nagel {Natiiriu. 

 Wochenschr., 1917, 15, 569-71, figs.l; see also Bot. Centralbl, 1917, 

 135, 359). A popular account of the very important results of the 

 recent experiments in macerating carboniferous impressions, in order to 

 render possible a microscopical examination of the epidermis of pre- 

 historic plants. By treatment with KCIO3 + HNO3 (Schulze's macera- 

 tion-mixture) the carboniferous plant-remains are reduced to a soft 

 peaty condition, which, after treatment with ammonia (whereby the 

 insoluble humus-acid produced during the oxidation is eliminated), 

 allows the epidermis to be detached from the subjacent layers and to be 

 studied in glycerin under the microscope. Some preparations of 

 Neuropteris ovata Hoffm., Anomozamites gracilis Nath., and Ctenoptens 

 Wolfiana Goth, are described. The method has been worked out 

 recently by Zeiller and others, and has systematically yielded great 

 results. A. G. 



Old Red Sandstone Plants showing Structure, from the Rhynie 

 Chert Bed, Aberdeenshire. Part I. Rhynia Gwynne-Vaughani 

 Kidston and Lang.— Pt. Kidston and W. H. Lang (Trans.:Roy. Soc. 

 Edinb., 51, 1917, 761-84, 10 pis. and figs.). An account of a new 

 genus of fossil plants summarized as follows :— Rhynia Gwynne-Vaughani 

 grew in gregarious fashion in a peaty soil practically composed of the 

 decaying remains of the same species. The land surface was probably 

 in the neighbourhood of water, and liable to periodic inundations. The 

 plant had no roots and no leaves. It was entirely composed of branched 

 cylindrical stems. The branched underground rhizomes were attached 

 to the peat by numerous rhizoids, most abundant on large, downwardly 

 directed bulges of the outer cortex. Some of the branches grew upwards 

 as tapering aerial stems. The aerial stems bore small lateral projections 

 irregularly scattered over the surface. Some of the projections^ possibly 



