Band 138. Nr. 19. XXXIX. Jahrgang. IL Bd. Nr. 19. 



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. Seott. Prof. Dr. Wm. Trelease. Dr. J. P. Lotsy. 



und der Redactions- Commissions- Mitglieder : 



Prof. Dr. Wm. Trelease, Dr. G. Bonaventura, Ä. D. Cotton, 



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



von zahlreichen Specialredacteuren in den verschiedenen Ländern. 



Dr. J. P. Lotsy, Chefredacteur. 



No. 45. 



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. 



Hill, J. B., A method for the dehydration of histological 

 material. (Botan. Gazette. LXI. p. 255—256. 1916.) 



In this note a method is described for the dehydration of histo- 

 logical material by glycerine. Afterwards the glycerine is removed 

 by washing in 95 per cent alcohol. Absolute alcohol is used to 

 complete the dehydration. The dehydration is accomplished uni- 

 formly, rapidly, and with a minimum of work and attention on the 

 part of the Operator. When imbedded by this method material 

 seems to cut better, since glycerine seems to harden less than alco- 

 hol. Material may be stored in the concentrated glycerine if it be 

 desirable to postpone the imbedding process. Jongmans. 



Knudson, L., Cambial activity in certain horticul tu ral 

 plants. (Bull. Torrey Botan. Club. XLIII. p. 533—537. 1916.) 



There is a scarcity of data respecting the season of cambial 

 activity in woody plants. The cambial activity in Vitis labrusca 

 began in the end of May and ceased before August 9. The cambial 

 activity in the peach began at the time of the opening of the buds, 

 in contrary to the condition found in the larch, grape and apple, 

 where it begins as the leaves are more or less completely developed. 

 In each case the cambial activity in the apple began before May 

 15. The most rapid increase began just after the leaves had attained 

 füll size. Mention should be made of the fact that no evidence was 

 obtained to indicate that phloem formation continued later than 

 xylem formation. Jongmans. 



Botan. Centralblatt. Band 138. 1918 19 



