Band 105. Nr. 10. XXVIII. Jahrgang. II. Bd. Nr. 10. 



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. 



Prof. Dr. R. v. Wettstein. Prof. Dr. Ch. Flahault. Dr. J. P. Lotsy. 



und der Redactions-Commissions- Mitglieder : 



Prof. Dr. Wm. Trelease und Dr. R. Pampanini. 



von zahlreichen Specialredacteuren in den verschiedenen Ländern 



Dr. J. P. Lotsy, Chefredacteur. 



No. 36. 



Abonnement für das halbe Jahr 14 Mark 

 durch alle Buchhandlungen und Postanstalten. 



1907. 



Alle für die Redaction bestimmten Sendungen sind zu richten an Herrn 

 Dr. J. P. LOTSY, Chefredacteur, Leiden (Holland), Witte Singel a6. 



Smith, F. G., Morphology of the trunk and development of 

 the microsporangium of Cycads. (Botan. Gazette XLIII. p. 

 187—204. pl. 10. March. 1907.) 



The Stern of Zaniia ßoridana is a sympodium, with a vegetative 

 point at the base of each strobilus. The microsporangia occur in 

 groups of two to six forming sori, which are disposed either on the 

 abaxial face of the sporophyll {Ceratosaniia) , or on the flanks {Zatniä). 

 The archesporium is a Single hypodermal cell, which usually divides 

 first anticlinally then periclinally. The outer plate of four cells forms 

 the wall, which m the mature microsporangium consists of four to 

 seven laj'ers. The tapetum is derived from sporogenous tissue; its 

 cells divide mitotically, and often contain two nuclei. The reduction 

 number of chromosomes in Zainia and Ceratosaniia is twelve. 



M. A. Chrysler. 



Anonymus. The origin of Gymnosperms. Discussion at the 

 Linnean Societ}' of London on March 15, and May 3, 1906. 

 (New Phytologist. Vol. V. p. 68 and 141. 1906.) 



A füll report of a discussion, opened by four addresses by 

 Prof. F. W. Oliver (Introductory), Mr. E. A. N. Arber (The Earlier 

 Geological Record of the True Ferns), Prof. A. C. Seward (The 

 Araiicarieae and the Origin of Conifers) and Dr. D. H. Scott. 



Arber (Cambridge). 



Botan. Centralblatt. Band 105. 19Ö7. 16 



