189^J MICROSCOPICAL JOURNAL. 181 



Notes on Microscopy. 



J. H. COOKE. 



Injection Staining. — Professor Robertson, m. a., of 

 St. Andrew's University, finds that there are many 

 plants which do not admit of the use of the filter pump 

 for injection-staining or of treatment by the well-known 

 method of Von Hohnel. For such specimens, he sug- 

 gests an alternative method, which he thinks will be 

 found useful, both to private workers and for classes. A 

 piece of india-rubber tubing, eight or more feet in length, 

 is securely wired to the end of a glass funnel. The ap- 

 paratus is fixed at a convenient height, and a compres- 

 sor clip is affixed to the free end of the tubing. A sec- 

 tion of the stem to be injected is cut smooth and round, 

 and is securely wired in the lower free end of the tube. 

 A weak aqueous solution of fuschin is poured into the 

 funnel, the compresser clip is removed, and a beaker is 

 placed below to receive the drippings. After a few 

 hours it will be found that much of the solution has pass- 

 ed through the conducting elements, staining them en 

 route. The stem is then affixed to a second apparatus and 

 treated in a similar manner with a weak solution of picric 

 acid. The second treatment darkens the stained ele- 

 ments and fixes the tissue. If the specimen is intended 

 for sectioning, it should finally be placed in ninety per 

 cent alcohol for a few days, after which it will be ready 

 for the microtone. 



Culture Cell. — The following method of making a 

 culture cell whereby the various stages in the propaga- 

 tion of the diatomacesB may be directly observed under 

 the microscope is both simple and effective. It was first 

 suggested by Dr. P. Miquel, and has since been used by 

 him in his laboratory with considerable success. To a 

 glass slip cement a glass ring out of the side of which a 

 small piece has been cut. Cover this with a cover-glass. 



