Band 138. Nr. 11. XXXIX. Jahrgang. IL Bd. Nr. 11. 



Botanisches Centralblatt. 



Referierendes Organ 



der 



Association Internationale des Botanistes 

 für das Gesamtgebiet der Botanik. 



Herausgegeben unter der Leitung 

 des Präsidenten: des Vice- Präsidenten: des Secretärs: 



Dr. D. H. Scott. Prof. Dr. Wm. Trelease. Dr. J. P. Lotsy. 



und der Redactions-Commissions- Mitglieder : 



Prof. Dr. Wm. Trelease, Dr. C. Bonaventura, A. D. Cotton, 



Prof. Dr. 0. Wehmer und Mag. C. Christensen. 



von zahlreichen Specialredacteuren in den verschiedenen Ländern. 



Dr. J. P. Lotsy, Chefredacteur. 



No. 37. 



Abonnement für das halbe Jahr 15 Mark 

 durch alle Buchhandlungen und Postanstalten. 



1918. 



Alle für die Redaction bestimmten Sendungen sind zu richten an: 

 Redaction des Botanischen Centr alblattes, Haarlem (Holland), Spaarne 17. 



Lloyd, F. E., The Abscission of Flo wer-buds and Fruits 

 i n Gossypium, and its Relation to Environmental Chan- 

 ges. (Trans. Roy. Soc. Canada. Series 3. Vol. X. Sect. IV. p. 

 55—61. Sept. 1916.) 



This article is an abstract of a paper read May, 1916. The pur- 

 pose of the work was to determine a) the method of abscission or 

 'shedding' in the fiower buds and fruits in the cotton plant, Gossy- 

 pium herbaceum; and b) the cause, or causes, leading up to shed- 

 ding in the field. 



The method of abscission consists fundamentally in the altera- 

 tion of cell-membranes by hydrolysis, so that one transverse tier of 

 cells is set free from the next tier above. 



It is concluded that shedding is mainly due to the depletion of 

 moisture in the deeper soil, and irrigation and better soil manipu- 

 lation are indicated as remedies. Shedding may also be due to 

 other causes, for instance the destruction of the pollen by water 

 shortly after pollination, or insect injury. 



Other points, such as the determination of the period between 

 the imposition of the Stimulus and the final completion of the re- 

 sponse following a variety of Stimuli, are also dealt with. 



The data upon which the above results rest are not given in 

 füll, but will appear elsewhere. M. G. Aikman (Kew). 



Dymes, T. A., The Seed-Mass and Dispersal of Helleboras 

 Joeüdus, Linn. (Journ. Linn. Soc. Bot. XLIII. p. 433—455. 1 pl. 1916.) 



This paper deals with the results of observations made in the 



Botan. Centralblatt. Band 13a 1918. 11 



