. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 217 



five hours, again washed, treated for five hours with sodium sulph- 

 alizai nate, washed, dehydrated, and mounted. 



Fo. reduction of silver, in silver-impregnation processes, formol- 

 gljcerin is recommended. 



The author discusses Apatliy's gold chloride method of staining 

 nerve-fibril preparations. After ])rolonged immersion in a gold chloride 

 solution, the sections are placed in a 1 p.c. formic acid solution and 

 exposed to bright sunlight. In vi(!W of the uncertainty caused by 

 possible failure of sunlight, it is recommended that the whole process 

 should be repeated twice. Good results have thus been obtained. 



In conchision, the author gives a detailed discussion of Cajal's silver 

 methods and of certain modifications. 



Methods for Demonstrating Nuclear Structure.* — H. Raabe has 

 carried out a research upon the nuclear division of Amcpyhldium para- 

 siticum, and has found certain fixing and staining methods of service. 

 For fixing the preparations he recommends the use of Schaudinn's fluid ; 

 for staining, Delafield's or Bohmer's haematoxylin, picrocarmin, Unna, 

 Pappenheim, and Romanowsky stains were employed. The most useful 

 was hsematoxylin, applied according to the method of Siedlecki. After 

 staining for 24 hours, the preparation was decolorized in 50 p.c. acid 

 alcohol and then immersed in 50 p.c. alcohol containing ammonia. 

 Grood results were also obtained when the acid was not neutralized by 

 subsequent alkaline treatment. 



Staining Plasma-cells. j — By the use of a staining-fluid containing 

 acridin red (G-riibler), L. Stropeni has obtained good results. The tissue 

 is fixed in alcohol, sublimate or Zenker's fluid, and thoroughly washed in 

 running water. After embedding and cutting, the sections are fixed to 

 slides, and the paraffin is removed in the usual manner. They are then 

 treated for thirty to forty-five minutes with the stain (methyl-green * 05, 

 acridin-red • 25, methyl-alcohol 30, glycerin 20, 1-2 p.c. phenol solution 

 to 100), decolorized rapidly with absolute alcohol, treated with xylol, 

 and mounted in balsam. 



New Method of Staining the Tubercle Bacillus. | — T. Ishiwara 

 stains with petrol-ether-carbol-fuchsin, decolorizes with 25 p.c. nitric 

 acid, and afterwards with 70 p.c. alcohol, and subsequently stains with 

 aqueous saturated solution of methylen-blue. 



The petrol-ether is shaken up with distilled water (1 to B), and then 

 filtered. To the filtrate one-fourth of its volume of carbol-fucbsin is 

 added. 



It is claimed that the granular appearance of the tubercle bacillus is 

 well demonstrated by this method. 



In an addendum the author gives the following modification of the 



* Arch. Zool. Exper., x. (1912) pp. .371-98. 



t Zeitscbr. wiss. Mikrosk,, xxix. (1912) pp. 302-5. 



X Centralbl. Bakt., Ixviii. (1913) p. 113. 



April 16th, 1913 Q 



