Bd. XCVI. Nr. 14. XXV. Jahrgang. 



Botanische« Centralblatt, 



Referirendes Organ 



der 



Association Internationale des Bofanistes 



für das Gesamrntgebiet der Botanik. 



Herausgegeben unter der Leitung 

 des Präsidenten: des Vice-Präsidenten: des Secretärs : 



Prof. Dr. K. Goebel. Prof. Dr. F. 0. Bower. Dr. J. P. Lotsy. 



und der Redactions-Commissions-Mitglieder : 



Prof. Dr. Ch. Flahault und Dr. Win. Trelease. 



von zahlreichen Specialredacteuren in den verschiedenen Ländern. 

 Dr. J. P. LotSy, Chefredacteur 



No. 40. 



Abonnement für das halbe Jahr 14 Mark 



durch alle Buchhandlungen und Postanstalten. 



1904, 



Alle für die Redaction bestimmten Sendungen sind zu richten an Herrn 

 Dr. J. P. LOTSY, Chefredacteur, Leiden (Holland), Rijn-en Schiekade 113. 



Plowman, A. B., The Celloidin Method with Hard 

 Tissues. (Botanical Gazette. Vol. XXXVII. 1904. p. 457 

 —461.) 



This is a detailed description of Prof. E. C. Jeffrey 's modification 

 of the celloidin method and is designed chiefly for the study of woody 

 tissues. 



Dead and dry tissues should be boiled repeatedly to drive out the 

 air. An air pump may also be necessary. Living material may be fixed 

 in the following Solution: 



Mercuric chloride, saturated Solution in 30°/o alcohol ... 3 parts. 



Picric acid, saturated Solution in 30°/o alcohol 1 part. 



After twenty-four hours pass the material through 40, 50, 60, 70 

 and 80 per cent. alcohol, allowing each grade to act for twelve to twenty- 

 four hours. The 80°/o alcohol should have enough iodine in it to keep 

 it of a deep brown color. 



Treat for three or four days with a ten per cent. aqueous Solution 

 of commercial hydrofluoric acid in order to remove mineral deposits. 



Dehydrate again in 30, 50, 70, 90 per cent. and absolute alcohol, 

 allowing twelve hours in each grade. The absolute alcohol should be 

 changed at least once. 



Treat with a series of celloidin Solutions, 2, 4, 6, 8, 10, 12, 14, 16, 

 18, and 20 per cent. of celloidin dissolved in equal parts of ether and 

 absolute alcohol, allowing each grade to act for twelve to eighteen 

 hours. During this process keep the temperature at 50° to 60 u C, 

 cooling the bootle when changing from one grade to another. After the 

 20°/i) Solution is reached, gradually add dry celloidin until the mixture in 

 the bottle becomes quite firm. The blocks of material with some 

 adhering celloidin should be hardened for twelve hours in Chloroform 

 and should then be transferred to equal parts of 95°/,, alcohol and 

 glycerine where they should remain a few days before cutting, but where 

 they may be kept indefinitely. 



Cut in the usual way. Before staining, the celloidin may be 

 removed by treating for a few minutes in ether. Erlich's haematoxylin 



Botan. Centralbl. Bd. XCVI. 1904. 22 



