Band 105. Nr. 12. XXVIII. Jahrgang. IL Bd. Nr. 12. 



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. 38. 



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 26. 



Report of the Third International Conference on Genetics. 

 ^•^06. (Royal Horticultural Society; Ed. b}'^ Rev. W. Wilks, Secretary.) 



The report opens with a füll account of the meetings of te Con- 

 ference, and notes are given in explanation of the numerous exhibits 

 made in the Royal Horticultural Society's Hall in illustration of the 

 laws of hybridisation and inheritance. The numerous papers read 

 before the Conference are then printed in füll and occupy 390 pages; 

 of these only a few of the most important can be noticed here. 



In his Presidential Address Mr. W. Bateson dealt with the 

 progress of genetic research since the first Conference held in 1899. 

 He described the great advance in knowledge of the laws of heredity 

 which followed the rediscovery of Mendel's papers, and proposed 

 the term Genetics to designate the science thus initiated. In illustra- 

 tion of this advance Mr. Bateson described the recent change in 

 our conception of the ideas conveyed by the expressions "pure-bred" 

 and "reversion". He emphasised the importance of the idea of sym- 

 metry in relation to the processes of segregation which underly the 

 visibly Mendelian behaviour of characters. 



Johannsen, W., Does Hybridisation increase Fluctuating 

 Variability? (p. 98—113.) 



The author gave a füll discussion of his theory of pure lines. 

 A pure line he defined as being simply a group of organisms des- 

 cended (by continued self-fertilisation) from a Single ancestor. He 

 brought forward evidence to show that on crossing together two 

 distinct pure lines the resulting hybrids were no more variable than 

 either of the parent lines, the character dealt with being weight of 

 seeds in broad beans {Phaseolus vulgaris). 



Botan. Centralblatt. Band W>. 1%7. 19 



