420 Morphologie etc. — Physiologie. 



since it consists of an isolated ovule. The male sporangiophores 

 having been related with some show of probability to the disc of 

 sporophylls in the Bennettitales , the authors suggest that the Single 

 ovule now developed at the apex of the axillary structure in the 

 male female flowers of Welwitschia and in the female fiower of 

 Ephedra represents the many ovules and interseminal scales of 

 such a flower as Cycadeoidea fused together. 



Agnes Arber (Cambridge). 



Thompson, W. P., The Anatomy and Relationships of the 



Gnetales I. The Genus Ephedra. (Ann. Bot. XXVI. p. 1077-1104. 



4 pl. 4 textfig. 1912.) 



The author has studied the anatomy of a large number of spe- 



cies of Ephedra, and finds that great uniformity of structure pre- 



vails throughout the genus. 



The priraary vascular bundles run regularly through one mter- 

 node and lose themselves in a nodal girdle oftracheides. Throughout 

 the internode their structure is endarch, but at the node occasional 

 Clements like transfusion tracheides are present in a centripetal 

 direction. The leaf-traces are double and the two Strands are inser- 

 ted separately, usually with a vascular bündle between. The tra- 

 cheides of the secondary wood are characterised by the arrangement 

 of the pits both in the Abietinean and Araucarian fashion. The 

 vessels have perforations which represent bordered pits. Transitions 

 between tracheides and vessels are remarkably complete. The ves- 

 sels are few in number and of a primitive character in the seedling. 

 The wood-parenchyma cells resemble tracheides in many features. 

 The medullary rays of the first-formed secondary wood are unise- 

 riate, and from these the broad rays of the adult are derived. The 

 bast is typically Gymnospermous. 



The author concludes that the idea of Cycadalean and Bennetti- 

 talean affinity receives little support from the anatomy of Ephedra. 

 On the other hand, there are many points which are in favour of 

 Coniterous relationship: the arrangement of the primary vascular 

 bundles, double leaf-trace, arrangement of structure of pits on the 

 tracheides, bars of Sanio, tertiary spirals, trabeculae and resin pla- 

 tes, primitive uniseriate lignified rays, wood-parenchyma, and 

 endarch vascular bundles of the leaf. The Gnetales do not appear 

 to have arisen from any modern group of Conifers, but rather from 

 or close to the base of the Coniferous line. An Angiospermous 

 affinity is indicated by the possession of true vessels, broad rays, 

 formation of broad rays by fusion , and Separation of the leaf-traces 

 on the stem. Agnes Arber (Cambridge). 



Deleano, N. F., Studien über den Atmungsstoffwechsel 

 abgeschnittener Laubblätter. (Jahrb. wiss. Bot. LI. p. 541— 

 592. 1912.) 



Bei der normalen Atmung abgeschnittener Blätter des Wein- 

 stocks werden bis zu 100 Std. nur Kohlehydrate, hauptsächlich 

 Stärke, in Kohlendioxyd verwandelt. Die Menge der Eiweisskörper 

 bleibt während dieser Zeit erhalten. Auch an dem Gehalt der 

 Stickstoffverbindungen, die im Zellsaft gelöst sind, tritt keine Ver- 

 änderung auf. . ^ . A* 

 Nachdem sämtliche Stärke veratmet ist, ändert sich der At- 



