Band 122. Nr. 11. XXXIV. Jahrgang. I. Bd. Nr. 11. 



Botanisches Centralblatt. 



Referirendes Organ 



der 



Association Internationale des Botanistes 

 für das Gesamtgebiet der Botanik. 



Herausgegeben unter der Leitung 

 des Präsidenten: des Vice- Präsidenten : des Secretärs: 



Prol. Dr. E. Warming. Prof. Dr. F. W. Oliver. Dr. J. F. Lotef . 



und der Redactions-Commissions- Mitglieder : 



Prof. Dr. Wm. Treleass, Dr. C. Bonaventura, A. D. Gotton, 



Prof. Dr. C. Wehmer und Dr. C. H, Ostenfeld. 



von zahlreichen Specialredacteuren in den verschiedenen Ländern. 



Dr. J. P. Lotsy, Chefredacteur. 



m. 11. 



Abonnement für das halbe Jahr 14 Mark 



durch alle Buchhandlungen und Postanstalten. 



1913. 



Alle für die Redaction bestimmten Sendungen sind zu richten an: 

 Redaction des Botanischen Centralblattes, Haarlem (Holland), Spaarne 17. 



Bailey, J. W., The Evolutionary History of the Foliar 

 Ray in the Wood of the Dicoty led on s: and its Phylo- 

 genetic Sign i f icance. (Ann. Bot. XXVI. 103. p. 647— 661. 2 pl, 

 july 1912.) 



The author briefly summarisis Kam es' and his own conclusions 

 on the broad and "falsa" rays of the Fagales. Further study of 

 Dicotyledonous plants has strongly confirmed the conclusions reached 

 with regard to the origin, development and dissecting effect of foliar 

 rays, and their importance in the evolution of modern Angiosperms. 

 He considers that the central cylinder cf primitive Angiosperms 

 was tubulär or siphonostelic, with strongly developed secondary 

 growth; uniseriate or linear rays -only were present in the wood. 

 but in warmer mesozoic times sheets of storage tissue were built 

 up from congeries of uniserate rays, about the persistent leaf-traces 

 of evergreen Angiosperms, these were subsequently extended above 

 the node, both vertically and horizontally. The primitive t5^pe of 

 ray still persist, more or less unaltered, in certain primitive fami- 

 lies e. g. Casuarinaceae. The primitive foliar ray has been modified 

 during later geological periods, the individual units of the aggrc- 

 gating mass of foliar ray tissue have become diffused throughout 

 the wood, in most cases sufificiently to have caused the disappea- 

 rance of any evidence of the former connexion between multiseriate 

 raj's and the leaf-traces. 



Reduction of the foliar ray has occured in many families, resul- 

 ting in reversion to a primitive uniseriate condition. The author 

 gives instances, from the Fagales, to shew the importance of expe. 



Botan. Centralblatt. Band 122. 191.3. 15 



